Exhaust Laws by State 2026

	State	Status↓
	California	State has objective method for measuring exhaust noise. and is trialling sound-activated enforcement systems from 2022 through 2027.
	Maine	State has objective method for measuring exhaust noise.
	Michigan	State has objective method for measuring exhaust noise.
	Montana	State has objective method for measuring exhaust noise.
	Nevada	State has objective method for measuring exhaust noise.
	Oregon	State has objective method for measuring exhaust noise.
	Pennsylvania	State has objective method for measuring exhaust noise.
	New York	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise. as well as cutouts, bypasses or other similar devices.
	Arkansas	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Colorado	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Delaware	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Florida	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Hawaii	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Idaho	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Illinois	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Kentucky	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Louisiana	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Maryland	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Nebraska	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Oklahoma	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Rhode Island	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Virginia	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Washington	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	West Virginia	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Wisconsin	Prohibits mufflers that create excessive or unusual noise. \| Also prohibits modifying mufflers to make more noise.
	Alabama	Prohibits mufflers that create excessive or unusual noise.
	Arizona	Prohibits mufflers that create excessive or unusual noise.
	Connecticut	Prohibits mufflers that create excessive or unusual noise.
	Georgia	Prohibits mufflers that create excessive or unusual noise.
	Indiana	Prohibits mufflers that create excessive or unusual noise.
	Iowa	Prohibits mufflers that create excessive or unusual noise.
	Kansas	Prohibits mufflers that create excessive or unusual noise.
	Massachusetts	Prohibits mufflers that create excessive or unusual noise.
	Minnesota	Prohibits mufflers that create excessive or unusual noise.
	Mississippi	Prohibits mufflers that create excessive or unusual noise.
	Missouri	Prohibits mufflers that create excessive or unusual noise.
	New Hampshire	Prohibits mufflers that create excessive or unusual noise.
	New Jersey	Prohibits mufflers that create excessive or unusual noise.
	New Mexico	Prohibits mufflers that create excessive or unusual noise.
	North Carolina	Prohibits mufflers that create excessive or unusual noise.
	North Dakota	Prohibits mufflers that create excessive or unusual noise.
	Ohio	Prohibits mufflers that create excessive or unusual noise.
	South Carolina	Prohibits mufflers that create excessive or unusual noise.
	South Dakota	Prohibits mufflers that create excessive or unusual noise.
	Tennessee	Prohibits mufflers that create excessive or unusual noise.
	Texas	Prohibits mufflers that create excessive or unusual noise.
	Utah	Prohibits mufflers that create excessive or unusual noise.
	Vermont	Prohibits mufflers that create excessive or unusual noise.
	Wyoming	Prohibits mufflers that create excessive or unusual noise.
	Alaska	Not regulated at state level.

Alabama

(a) Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke, and no person shall use a muffler cut-out, bypass, a muffler without baffles or similar device upon a motor vehicle on a highway. (b) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. § 33-5-23. (a) The exhaust of every internal combustion engine used on any vessel shall be effectively muffled by equipment so constructed and used to muffle the noise of the exhaust in a reasonable manner. The use of cutouts is prohibited, except for vessels competing in a regatta or official boat race, and for such vessels while on trial runs.

Alaska

Regulated locally rather than at the state level.

Arizona

§ 28-955. Mufflers; noise and air pollution prevention; emissions control devices; civil penalty; exception (a) A motor vehicle shall be equipped at all times with a muffler that is in good working order and that is in constant operation to prevent excessive or unusual noise. (b) A person shall not use a muffler cutout, bypass or similar device on a motor vehicle on a highway. (c) The engine and power mechanism of a motor vehicle shall be equipped and adjusted to prevent the escape of excessive fumes or smoke. (d) Beginning with motor vehicles and motor vehicle engines of the 1968 model year, motor vehicles and motor vehicle engines shall be equipped with emissions control devices that meet the standards established by the director of environmental quality. (e) A person who violates this section is subject to a civil penalty of at least one hundred dollars. (f) This section does not apply to an electrically powered motor vehicle.

Arkansas

§27-37-601. Noise or smoke-producing devices are prohibited. (a) Every motor vehicle shall, at all times, be equipped with a factory-installed muffler or one duplicating factory specifications, in good working order and in constant operation, to prevent excessive or unusual noise and annoying smoke. (b) No person shall use on a motor vehicle upon the public roads, highways, streets, or alleys of this state, nor shall any person sell for use on a motor vehicle upon the public roads, highways, streets, or alleys of this state, a muffler, other than as defined in subsection (a) of this section, cutout, bypass, similar device, or any type device which produces excessive or unusual noise or smoke. § 27-37-602. Cutouts prohibited. (a) The sale or use of cutouts on any motor-driven vehicle while on the public roads, highways, streets, and alleys of Arkansas is prohibited. (b) Any person found guilty in any court of Arkansas of violating this section, in whole or in part, shall be deemed guilty of a misdemeanor and subject to a fine of not less than ten dollars ($10.00) nor more than five hundred dollars ($500).

California

§ 27151. Modification of exhaust systems (a) No person shall modify the exhaust system of a motor vehicle in a manner that will amplify or increase the noise emitted by the motor of the vehicle so that the vehicle is not in compliance with the provisions of Section 27150 or exceeds the noise limits established for the type of vehicle in Article 2.5 (commencing with Section 27200). No person shall operate a motor vehicle with an exhaust system so modified. (b) For the purposes of exhaust systems installed on motor vehicles with a manufacturer’s gross vehicle weight rating of fewer than 6,000 pounds, other than motorcycles, a sound level of 95 dbA or less, when tested in accordance with the Society of Automotive Engineers Standard J1169 May 1998, complies with this section. Motor vehicle exhaust systems or parts thereof include but are not limited to nonoriginal exhaust equipment.

Colorado

Every motor vehicle subject to registration and operated on a highway shall at all times be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise, and no such muffler or exhaust system shall be equipped with a cut-off, bypass, or similar device. No person shall modify the exhaust system of a motor vehicle in a manner that will amplify or increase the noise emitted by the motor of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all of the requirements of this section. (1.5) Any commercial vehicle, as defined in section 42-4-235 (1) (a), subject to registration and operated on a highway, that is equipped with an engine compression brake device is required to have a muffler. (2) A muffler is a device consisting of a series of chamber or baffle plates or other mechanical designs for the purpose of receiving exhaust gas from an internal combustion engine and is effective in reducing noise. (3) Any person who violates subsection (1) of this section commits a class B traffic infraction. Any person who violates subsection (1.5) of this section shall, upon conviction, be punished by a fine of five hundred dollars. Fifty percent of any fine for a violation of subsection (1.5) of this section occurring within the corporate limits of a city or town, or within the unincorporated area of a county, shall be transmitted to the treasurer or chief financial officer of said city, town, or county, and the remaining fifty percent shall be transmitted to the state treasurer, credited to the highway users tax fund, and allocated and expended as specified in section 43-4-205 (5.5) (a), C.R.S. (4) This section shall not apply to electric motor vehicles.

Connecticut

Sec. 14-80. Mechanical equipment. (a) Each motor vehicle and the devices on such vehicle shall be operated, equipped, constructed, and adjusted to prevent unnecessary or unusual noise. (b) Each motor vehicle operated by an internal combustion engine shall be equipped, except as hereinafter provided, with a muffler or mufflers designed to prevent excessive, unusual, or unnecessary exhaust noise. The muffler or mufflers shall be maintained by the owner in good working order and shall be in use whenever the motor vehicle is operated. No person, including a motor vehicle dealer or repairer or a motorcycle dealer, shall install, and no person shall use, on a motor vehicle, a muffler or mufflers lacking interior baffle plates or other effective muffling devices, a gutted muffler, a muffler cutout or a straight exhaust except when the motor vehicle is operated in a race, contest or demonstration of speed or skill as a public exhibition pursuant to subsection (a) of section 14-164a, or any mechanical device which will amplify the noise emitted by the vehicle. No person, including a motor vehicle dealer or repairer or a motorcycle dealer, shall remove all or part of any muffler on a motor vehicle except to repair or replace the muffler or part for the more effective prevention of noise. No person shall use on the exhaust system or tailpipe of a motor vehicle any extension or device which will cause excessive or unusual noise. (c) The engine of every motor vehicle shall be equipped and adjusted to prevent excessive fumes or exhaust smoke. (d) All pipes carrying exhaust gases from the motor shall be constructed of and maintained with leak-proof metal. Exhaust pipes shall be directed from the muffler or mufflers toward the rear of the vehicle and shall be approximately parallel with the longitudinal axis of the vehicle and approximately parallel to the surface of the roadway, or shall be directed from the muffler upward to a location above the cab or body of the vehicle so that fumes, gases, and smoke are directed away from the occupants of the vehicle. Exhaust pipes on a passenger vehicle shall extend to the extreme rear end of the vehicle’s body, not including the bumper and its attachments to the body, or shall be attached to the vehicle in such a way that the exhaust pipes direct the exhaust gases to either side of the vehicle ensuring that fresh ambient air is located under the vehicle at all times. The Commissioner of Motor Vehicles may adopt regulations in accordance with the provisions of Chapter 54 to establish safety standards for passenger vehicles equipped with exhaust pipes located in front of the rear axle. (e) Every motor vehicle shall, when operated on a highway, be equipped with a horn in good working order and capable of emitting sound audible under normal conditions from a distance of not less than two hundred feet, but no horn or other warning device shall emit an unreasonably loud or harsh sound or a whistle. (f) No vehicle shall be equipped with, nor shall any person use on a vehicle, any siren, whistle, or bell as a warning signal device, except as otherwise permitted by this section. Any motor vehicle may be equipped with a theft alarm signal device that is so arranged that it cannot be used by the driver as an ordinary warning signal. Any authorized emergency vehicle may be equipped with a siren, whistle, or bell, capable of emitting sound audible under normal conditions from a distance of not less than five hundred feet and of a type approved by the Department of Motor Vehicles. Such signal shall not be used unless the vehicle is operated in response to an emergency call or in the immediate pursuit of an actual or suspected violator of the law, in which event the driver of the vehicle shall sound the signal when reasonably necessary to warn pedestrians and other drivers of the approach of the vehicle. (g) Any person who violates any provision of this section shall be fined one hundred fifty dollars for each offense.

Delaware

Title 11 § 4311. Mufflers; cutout prohibited (a) No person shall drive a motor vehicle, including a motorcycle, on a highway, including residential streets, unless such motor vehicle or motorcycle is equipped with a muffler in good working order and in accordance with manufacturer’s specifications and in constant operation to prevent excessive or unusual noise. (b) No person shall use a “muffler cutout” on any motor vehicle upon a highway. (c) It shall be unlawful to sell or offer for sale any muffler without interior baffle plates or other effective muffling devices or to sell or offer for sale any “gutted muffler,” “muffler cutout” or “straight exhaust.” (d) The provisions of this section shall only apply if there is not a violation of § 4311A of this title.

Florida

§ 316.272. Exhaust systems, prevention of noise (1) Every motor vehicle shall at all times be equipped with an exhaust system in good working order and in constant operation, including muffler, manifold pipe, and tailpiping to prevent excessive or unusual noise. In no event shall an exhaust system allow noise at a level which exceeds a maximum decibel level to be established by regulation of the Department of Environmental Protection as provided in s. 403.061(11) in cooperation with the Department of Highway Safety and Motor Vehicles. No person shall use a muffler cutout, bypass or similar device upon a vehicle on a highway. (2) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. (3) A violation of this section is a noncriminal traffic infraction, punishable as a nonmoving violation as provided in chapter 318. § 316.293. Motor vehicle noise (5) Noise abatement equipment modifications. (a) No person shall modify the exhaust system of a motor vehicle or any other noise-abatement device of a motor vehicle operated or to be operated upon the highways of this state in such a manner that the noise emitted by the motor vehicle is above that emitted by the vehicle as originally manufactured. (b) No person shall operate a motor vehicle upon the highways of the state with an exhaust system or noise-abatement device so modified

Georgia

§ 40-8-71. Exhaust system; prevention of noise, smoke, and fumes (a) Every motor vehicle shall at all times be equipped with an exhaust system, in good working order, and in constant operation, meeting the following specifications:
(1) The exhaust system shall include the piping leading from the flange of the exhaust manifold to and including the muffler or mufflers and tailpipes; (2) The use of flexible pipe shall be prohibited except on diesel tractors or according to manufacturers’ original specifications; (3) The exhaust emission point shall extend beyond the rear or outside of the passenger compartment. The trunk shall be considered as part of the passenger compartment; (4) The exhaust system and its elements shall be securely fastened, including the consideration of missing or broken hangers; and (5) There shall be no part of the exhaust system passing through the passenger compartment or any exposed stack so located that any individual entering or leaving the vehicle may be burned. (b) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. (c) It shall be unlawful for any person to sell or offer for sale any muffler which causes excessive or unusual noise or annoying smoke or any muffler cutout, bypass, or similar device for use on a motor vehicle or for any person to use, to sell, or to offer for sale any motor vehicle equipped with any such muffler, muffler cutout, bypass, or similar device. Any person violating this subsection shall be guilty of a misdemeanor.

Hawaii

§ 291-24.5. Motor vehicle muffler. (a) No person shall use on a public highway, sell, alter, or install a muffler which will noticeably increase the noise emitted by a motor vehicle above that emitted by the vehicle as equipped from the factory. (b) Any violation of this section shall constitute a violation and shall be enforceable by police officers. The fine for this violation shall be not less than $25 nor more than $250 for each separate offense. Any person who violates the provisions of this section may be issued a summons or citation for such violation.

Idaho

§ 49-937. Mufflers, prevention of noise (1) Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke, and no person shall use a muffler cut-out, bypass, or similar device upon a motor vehicle on a highway. When any motor vehicle was originally equipped with a noise-suppressing system or when any motor vehicle is required by law or regulation of this state or the federal government to have a noise-suppressing system, that system shall be maintained in good working order. No person shall disconnect any part of that system except temporarily in order to make repairs, replacements, or adjustments, and no person shall modify or alter that system or its operation in any manner, except to conform to the manufacturer’s specifications. No person shall knowingly operate and no owner shall knowingly cause or permit to be operated any motor vehicle originally equipped or required by any law or regulation of the state or the federal government to be equipped with a noise suppressing system while any part of that system is disconnected or while that system or its operation is modified or altered in any manner, except to conform to the manufacturer’s specifications. (2) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. (3) No person shall modify the exhaust system of a motor vehicle or a motorcycle in a manner that will amplify or increase the noise of the vehicle or motorcycle above that emitted by the muffler originally installed on the vehicle by the manufacturer. (4) A showing that the sound made by a passenger motor vehicle or motorcycle exceeds the maximum allowable decibel level shall be prima facie evidence of a violation of subsection (1) of this section. (5) No person shall sell, offer for sale, or install any noise-suppressing system or device which will produce excessive or unusual noise.

Illinois

§ 625 ILCS 5/12-602. Mufflers, prevention of noise Every motor vehicle driven or operated upon the highways of this State shall at all times be equipped with an adequate muffler or exhaust system in constant operation and properly maintained to prevent any excessive or unusual noise. No such muffler or exhaust system shall be equipped with a cutout, bypass, or similar device. No person shall modify the exhaust system of a motor vehicle in a manner that will amplify or increase the noise of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all the requirements of this Section.

Indiana

9-19-8-2. Muffler to be free from visually discernible conditions. A motor vehicle must be equipped with a muffler free from the following visually discernible conditions: (1) Exhaust gas leaks. (2) Alteration of muffler elements. (3) Deterioration of muffler elements. 9-19-8-3. Muffler or other noise dissipative device to meet certain conditions. A motor vehicle must be equipped with a muffler or other noise-dissipative device that meets the following conditions: (1) Is in good working order. (2) Is in constant operation to prevent excessive noise. 9-19-8-4. Equipment prohibited. A motor vehicle may not be equipped with any of the following: (1) A muffler cutout. (2) A bypass. (3) Any similar device.

Iowa

§ 321.436 Mufflers, prevention of noise. Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke, and no person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway.

Kansas

§ 8-1739 Mufflers and noise suppressing systems. (a) Every vehicle shall be equipped, maintained, and operated so as to prevent excessive or unusual noise. Every motor vehicle at all times shall be equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation, and no person shall use a muffler cut-out, bypass, or similar device. (b) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke.

Kentucky

§ 189.020. Equipment of vehicle not to be a nuisance or menace. Every vehicle when on a highway shall be so equipped as to make a minimum of noise, smoke, or other nuisance, to protect the rights of other traffic, and to promote public safety. § 189.140. Mufflers — Noise regulation. (1) Every motor vehicle with an internal combustion, steam, or air motor shall be equipped with a suitable and efficient muffler. No person while on a highway shall operate a motor vehicle with the muffler cut out or removed. No cutout shall be so arranged or connected as to permit its operation or control by the driver of any motor vehicle while in position for driving. (2) No person shall modify the exhaust system of a motor vehicle or an off-highway vehicle in a manner that will amplify or increase the noise emitted by the motor of such vehicle above that emitted by the muffler originally installed on the vehicle. The original muffler shall comply with all of the noise requirements of KRS Chapter 224 and regulations promulgated pursuant thereto. No person shall operate a motor vehicle with an exhaust system so modified. § 224.30-190 Modification of motor vehicle exhaust system to increase noise prohibited. No person shall modify the exhaust system of a motor vehicle in a manner that will amplify or increase the noise emitted by the motor of such vehicle, above that emitted by the muffler originally installed on the vehicle and the original muffler shall comply with all of the requirements of this chapter. No person shall operate a motor vehicle with an exhaust system so modified.

Louisiana

§ 32:352. Mufflers; requirements; prevention of excessive noise, fumes, and smoke A. Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise. B. No person shall use a muffler cut-out, bypass, or similar device upon a motor vehicle on a highway of this state. C. The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. § 32:353. Modification of exhaust systems No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise emitted by the motor of such vehicle, above that emitted by the muffler originally installed on the vehicle and the original muffler shall comply with all of the requirements of R.S. 32:352.

Maine

§ 1912. Mufflers

Muffler required. A person may not operate a motor vehicle unless that vehicle is equipped with an adequate muffler properly maintained to prevent excessive or unusual noise. For purposes of this subsection, “excessive or unusual noise” includes motor noise emitted by a motor vehicle that is noticeably louder than similar vehicles in the environment.
Cutouts prohibited. A muffler or exhaust system may not be equipped with a cutout, bypass or similar device.
Amplification prohibited. A person may not operate a motor vehicle with an exhaust system that has been modified when the result of that modification is the amplification or increase of noise emitted by the motor above that emitted by the muffler originally installed on the vehicle.
Exhaust system fastened to the engine. The entire exhaust system must be complete, without leakage and securely fastened to the engine block and frame.
Exception; racing meets. [2015, c. 206, § 9 (RP).]
Defense for noise violations by motor vehicles. The following are defenses to a violation of subsection 1 or 3. (a) If a muffler or exhaust system of a motor vehicle as defined in section 101, subsection 42, not including a motorcycle, does not emit noise in excess of 95 decibels as measured in accordance with standards and specifications outlined in standard J-1169 adopted by the Society of Automotive Engineers in May 1998, subsections 1 and 3 do not apply. A person served with a Violation Summons and Complaint charging a violation of subsection 1 or 3 must provide satisfactory evidence that the muffler or exhaust system does not emit noise in excess of 95 decibels as measured in accordance with standards and specifications outlined in standard J-1169 adopted by the Society of Automotive Engineers in May 1998. Measurements must be made by a participating certified inspection station.

Maryland

§ 22-402. Mufflers; prevention of noise; discharge of smoke; maximum period of idling (a) Mufflers. — Every motor vehicle with an internal combustion engine shall be equipped with an exhaust muffler system in good working order and in constant operation to prevent excessive or unusual noise, and no person may use a muffler cutout, bypass, or similar device on a motor vehicle on a highway. Noise levels in excess of those adopted by the Administrator under § 22-601 of this title are excessive. (b) Prevention of noise. — A person may not use on the exhaust or “tailpipe” of a motor vehicle any extension or other device to cause excessive or unusual noise. (c) Discharge of smoke; maximum period of idling. — (1) No motor vehicle may be operated, nor may the owner or lessee of a motor vehicle permit it to be operated, on any highway in this State unless the engine power and exhaust mechanism is equipped, adjusted, and operated to prevent: (i) The discharge of clearly visible smoke (comparable to smoke equal to or darker in shade than that designated as No. 1 of the Ringelmann Chart as published by the U.S. Bureau of Mines) in the exhaust emissions within the proximity of the exhaust outlet for more than 10 consecutive seconds; and (ii) The discharge of smoke from any other part of the engine in such amounts and of such opacity as to partially obscure persons or objects from view. (2) In this subsection, “smoke” means small gas-borne and airborne particles, exclusive of water vapor, from a process of combustion in sufficient numbers to be observable. (3) A motor vehicle engine may not be allowed to operate for more than 5 consecutive minutes when the vehicle is not in motion, except as follows: (i) When a vehicle is forced to remain motionless because of traffic conditions or mechanical difficulties over which the operator has no control; (ii) When it is necessary to operate heating and cooling or auxiliary equipment installed on the vehicle; (iii) To bring the vehicle to the manufacturer’s recommended operating temperature; or (iv) When it is necessary to accomplish the intended use of the vehicle. (4) For a period of 1 year from July 1, 1971, this subsection shall be enforced by issuance of a warning. One year from July 1, 1971, it shall be enforced in the same manner as other violations of this section. (5) This subsection does not apply to Class L (historic) vehicles. (d) “Muffler” defined. — In this section, “muffler” means a device designed for and effective in reducing noise while permitting the flow of gases. (e) Leakproof construction. — All mufflers and exhaust pipes carrying exhaust gases from the motor shall be of leakproof construction. § 22-609. Modification of exhaust system (a) Modification that increases sound prohibited. — A person may not modify the exhaust system or any other noise abatement device of a motor vehicle driven or to be driven on any highway in this State in such a way that the noise emitted by the vehicle exceeds that emitted by the vehicle as originally manufactured. (b) Operation of improperly modified vehicle prohibited. — A person may not drive on any highway in this State a motor vehicle with an exhaust system or noise abatement device modified in a way prohibited by subsection (a) of this section.

Massachusetts

Chapter 90 § 7. Brakes, Lights, and Other Equipment; Standards. Every motor vehicle so operated shall be provided with a muffler or other suitable device to prevent unnecessary noise and with a suitable bell, horn, or other means of signaling, with suitable lamps, and with a lock, key, or other device to prevent such vehicle from being set in motion by unauthorized persons, or otherwise contrary to the will of the owner or person in charge thereof.

Michigan

§ 257.707b. Exhaust system; requirements. (1) A motor vehicle, while being operated on a highway or street, shall be equipped with an exhaust system in good working order to prevent excessive or unusual noise and shall be equipped to prevent noise in excess of the limits established in this act. (2) For purposes of sections 707a to 707f, a motor vehicle does not include special mobile equipment. § 257.707c. Noise limitations; prohibitions. (1) After April 1, 1978, a motor vehicle shall not be operated or driven on a highway or street if the motor vehicle produces total noise exceeding 1 of the following limits at a distance of 50 feet except as provided in subdivisions (b)(iii) and (c)(iii): (a) A motor vehicle with a gross weight or gross vehicle weight rating of 8,500 pounds or more, a combination vehicle with a gross weight or gross vehicle weight rating of 8,500 pounds or more. (i) Ninety DBA if the maximum lawful speed on the highway or street is greater than 35 miles per hour. (ii) Eighty-six DBA if the maximum lawful speed on the highway or street is not more than 35 miles per hour. (iii) Eighty-eight DBA under stationary run-up test. (b) A motorcycle or a moped: (i) Eighty-six DBA if the maximum lawful speed on the highway or street is greater than 35 miles per hour. (ii) Eighty-two DBA if the maximum lawful speed on the highway or street is not more than 35 miles per hour. (iii) Ninety-five DBA under stationary run-up test 20 inches from the end of the tailpipe. (c) A motor vehicle or a combination of vehicles towed by a motor vehicle not covered in subdivision (a) or (b): (i) Eighty-two DBA if the maximum lawful speed on the highway or street is greater than 35 miles per hour. (ii) Seventy-six DBA if the maximum lawful speed on the highway or street is not more than 35 miles per hour. (iii) Ninety-five DBA under stationary run-up test 20 inches from the end of the tailpipe. (2) A dealer shall not sell or offer for sale for use upon a street or highway in this state a new motor vehicle manufactured after April 1, 1978, which produces a maximum noise exceeding the following limits: (a) A motor vehicle with a gross vehicle weight rating of 8,500 pounds or more–83 DBA. (b) A motorcycle or a moped–83 DBA. (c) A motor vehicle not covered in subdivision (a) or (b)—80 DBA. (3) A person shall not operate a vehicle on a highway or street if the vehicle has a defect in the exhaust system that affects sound reduction, is not equipped with a muffler or other noise dissipative device, or is equipped with a cutout, bypass, amplifier, or a similar device. (4) A person, either acting for himself or herself or as the agent or employee of another, shall not sell, install, or replace a muffler or exhaust part that causes the motor vehicle to which the muffler or exhaust part is attached to exceed the noise limits established by this act or a rule promulgated under this act. (5) A person shall not modify, repair, replace, or remove a part of an exhaust system causing the motor vehicle to which the system is attached to produce noise in excess of the levels established by this act, or operate a motor vehicle so altered on a street or highway. (6) A dealer shall not sell a used or secondhand motor vehicle for use upon a street or highway which is not in compliance with this act.

Minnesota

§ 169.69 Muffler Every motor vehicle shall at all times be equipped with a muffler in good working order which blends the exhaust noise into the overall vehicle noise and is in constant operation to prevent excessive or unusual noise, and no person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a street or highway. The exhaust system shall not emit or produce a sharp popping or crackling sound. Every motor vehicle shall at all times be equipped with such parts and equipment so arranged and kept in such state of repair as to prevent carbon monoxide gas from entering the interior of the vehicle. No person shall have for sale, sell or offer for sale or use on any motor vehicle any muffler that fails to comply with the specifications as required by the commissioner of public safety.

Mississippi

§ 63-7-55. Mufflers Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke. No person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway.

Missouri

§ 307.170. Other equipment of motor vehicles—violations, penalty 2. Muffler cutouts: Muffler cutouts shall not be used and no vehicle shall be driven in such manner or condition that excessive and unnecessary noises shall be made by its machinery, motor, signaling device, or other parts, or by any improperly loaded cargo. The motors of all motor vehicles shall be fitted with properly attached mufflers of such capacity or construction as to quiet the maximum possible exhaust noise as completely as is done in modern gas engine passenger motor vehicles. Any cutout or opening in the exhaust pipe between the motor and the muffler on any motor vehicle shall be completely closed and disconnected from its operating lever and shall be so arranged that it cannot automatically open, or be opened or operated while such vehicle is in motion.

Montana

§ 61-9-435 Exhaust noise limitation. (1) Except as provided in subsection (3), a person may not operate a motor vehicle with an exhaust system that emits noise in excess of 95 decibels, as measured by the Society of Automotive Engineers’ standard j1169 (May 1998). (2) A person charged with violating this section may not be convicted if the person had reasonable grounds to believe that the vehicle was not operated in violation of the standard in subsection (1). (3) This section does not apply to a motorcycle or quadricycle that is subject to 61-9-418.

Nebraska

§ 60-6,286. Muffler or noise-suppressing system; prevention of fumes and smoke; requirements Every vehicle shall be equipped, maintained, and operated so as to prevent excessive or unusual noise. No person shall drive a motor vehicle on a highway unless such motor vehicle is equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation. It shall be unlawful to use a muffler cutout, bypass, or similar device on any motor vehicle upon a highway. The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. § 60-6,371. Exhaust or intake muffler; change; increase of noise; prohibited No person shall modify or change the exhaust muffler, the intake muffler, or any other noise-abatement device of a motor vehicle in a manner such that the noise emitted by the motor vehicle is increased above that emitted by the vehicle as originally manufactured. Procedures used to establish compliance with this section shall be those used to establish compliance of a new motor vehicle with the requirements of sections 60-6,363 to 60-6,374.

Nevada

§ 484D.415 Mufflers: Prevention of emissions.

Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent emissions greater than those allowed by rules and regulations established by the Department. No person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway.
The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke.

New Hampshire

266:59 Muffler; Prevention of Noise. I. Every motor vehicle shall at all times be equipped with a muffler as defined in RSA 259:66, in good working order and in constant operation to prevent excessive or unusual noise, and no person shall use a muffler cutout, bypass or similar device upon a motor vehicle on a way. II. The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes, smoke, flame, gas, oil, or fuel residue. III. [Repealed.] IV. No person shall operate a motor vehicle with a straight pipe exhaust system; “straight pipe exhaust system” means any straight-through exhaust system that does not contain baffles or otherwise does not meet the definition of muffler in RSA 259:66. Any person who violates the provisions of this paragraph shall be guilty of a violation and shall be fined not less than $100 for a first offense, not less than $250 for a second offense in a calendar year, and not less than $500 for a third or subsequent offense in a calendar year.

New Jersey

§ 39:3-70. Mufflers Every motor vehicle having a combustion motor shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and no person shall use a muffler cut-out, bypass, or similar device upon a motor vehicle on a highway.

New Mexico

§ 66-3-844. Mufflers; prevention of noise; emission control devices A. Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise, and no person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway. B. The muffler, emission control equipment or device, engine, and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. C. Every registered gasoline-fueled motor vehicle manufactured or assembled, commencing with the 1968 models, shall at all times be equipped and maintained in good working order with the factory-installed devices and equipment or their replacements designed to prevent, reduce, or control exhaust emissions or air pollution.

New York

Vehicle and Traffic Law § 375. Equipment 31. Mufflers and exhaust systems. Prevention of noise. Every motor vehicle, operated or driven upon the highways of the state, shall at all times be equipped with an adequate muffler and exhaust system in constant operation and properly maintained to prevent any excessive or unusual noise and no such muffler or exhaust system shall be equipped with a cut-out, bypass, or similar device. No person shall modify the muffler or exhaust system of a motor vehicle in a manner that will amplify or increase the noise emitted by the motor or exhaust system of such vehicle above that emitted by the muffler or exhaust system originally installed on the vehicle and such original muffler and exhaust system shall comply with all the requirements of this section. A muffler is a device consisting of a series of chambers or baffle plates, or other mechanical designs for the purpose of receiving exhaust gas from an internal combustion engine, and effective in reducing noise. An exhaust system is a series of mechanical devices for the purpose of receiving exhaust gas from an internal combustion engine and expelling it into the atmosphere.

North Carolina

§ 20-128. Exhaust system and emissions control devices (a) No person shall drive a motor vehicle on a highway unless such motor vehicle is equipped with a muffler, or other exhaust system of the type installed at the time of manufacture, in good working order, and in constant operation to prevent excessive or unusual noise, annoying smoke and smoke screens. (b) It shall be unlawful to use a “muffler cut-out” on any motor vehicle upon a highway. (c) No motor vehicle registered in this State that was manufactured after model year 1967 shall be operated in this State unless it is equipped with emissions control devices that were installed on the vehicle at the time the vehicle was manufactured and these devices are properly connected. (d) The requirements of subsection (c) of this section shall not apply if the emissions control devices have been removed for the purpose of converting the motor vehicle to operate on natural or liquefied petroleum gas or other modifications have been made in order to reduce air pollution and these modifications are approved by the Department of Environment and Natural Resources.

North Dakota

§ 39-21-37. Muffler — Prevention of noise and smoke.

Every motor vehicle must at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke, and no person may use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway.
The engine and power mechanism of every motor vehicle must be so equipped and adjusted as to prevent the escape of excessive fumes or smoke.

Ohio

§ 4513.22. Mufflers; excessive smoke or gas (A) Every motor vehicle and motorcycle with an internal combustion engine shall at all times be equipped with a muffler that is in good working order and in constant operation to prevent excessive or unusual noise, and no person shall use a muffler cutout, by-pass, or similar device upon a motor vehicle on a highway. Every motorcycle muffler shall be equipped with baffle plates. No person shall own, operate, or have in the person’s possession any motor vehicle or motorcycle equipped with a device for producing excessive smoke or gas, or so equipped as to permit oil or any other chemical to flow into or upon the exhaust pipe or muffler of such vehicle, or equipped in any other way to produce or emit smoke or dangerous or annoying gases from any portion of such vehicle, other than the ordinary gases emitted by the exhaust of an internal combustion engine under normal operation. (B) Whoever violates this section is guilty of a minor misdemeanor.

Oklahoma

Title 47 § 12-402. Mufflers, Prevention of Noise A. Every vehicle shall be equipped, maintained, and operated so as to prevent excessive or unusual noise. Every motor vehicle shall at all times be equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation, and no person shall use a muffler cut-out, bypass, or similar device. No person shall modify the exhaust system of a motor vehicle in any manner which will amplify or increase the noise or sound emitted louder than that emitted by the muffler originally installed on the vehicle. B. The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke, or both.

Oregon

§ 815.250 Operation without proper exhaust system; exemptions; penalty. (1) A person commits the offense of operation without proper exhaust system if the person drives or moves on any highway or owns and causes or knowingly permits to be driven or moved on any highway a motor vehicle that is not equipped with an exhaust system that meets the requirements under this section. (2) An exhaust system only meets the requirements of this section if all of the following apply: (a) The exhaust system must be in good working order. (b) The exhaust system must be in constant operation. (c) The exhaust system must meet noise emission standards determined by the Department of Environmental Quality to be substantially equivalent to the following standards based upon a stationary test conducted at a distance of 25 feet in accordance with procedures established by the Department of Environmental Quality: I. Vehicle type: Motor vehicles required to establish a registration weight under ORS 803.430 and commercial buses Maximum level, dBA: 94 dBA if model year before 1976; 91 dBA if model year 1976 and after II. Vehicle type: Motorcycles and mopeds Maximum level, dBA: 94 dBA if model year before 1976; 91 dBA if model year 1976; 89 if model year after 1976 III. Vehicle type: motor vehicles not described under I or II Maximum level, dBA: 92 dBA if model year before 1976; 88 dBA if model year 1976 and after (3) This section does not apply to the following vehicles: (a) Vehicles of special interest that are registered under ORS 805.020 and that are: (A) Equipped with original manufacturer’s equipment and accessories, or their equivalent, and that are maintained in safe operating condition; or (B) Street rods that conform to ORS 815.107. (b) Road machinery, road rollers, or farm tractors. (c) Antique motor vehicles that are maintained as collectors’ items and used for exhibitions, parades, club activities, and similar uses, but not used primarily for the transportation of persons or property. (4) The court in its discretion may dismiss a citation issued for violation of the offense described in this section if evidence is presented that the exhaust system complies with or has been repaired or modified to comply with the requirements under this section. (5) The offense described in this section, operation without proper exhaust system, is a Class C traffic violation.

Pennsylvania

§ 4523 Exhaust systems, mufflers, and noise control. (a) Compliance with established sound levels. —Every motor vehicle operated on a highway shall be constructed, equipped, maintained, and operated so as not to exceed the sound level for the vehicle as prescribed in regulations promulgated by the department. The test procedures and instrumentation to be utilized shall also be established by regulation. (b) Compliance with exhaust requirements. —In addition to any requirements established under sections 4531 (relating to emission control systems) and 4532 (relating to smoke control for diesel-powered motor vehicles), every motor vehicle shall be constructed, equipped, maintained, and operated so as to prevent engine exhaust gases from penetrating and collecting in any part of the vehicle occupied by the driver or passengers. (c) Mufflers and related equipment. —Every motor vehicle shall be equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation and no muffler or exhaust system shall be equipped with a cutout, bypass or similar device. (d) Unauthorized modification of equipment. —No person shall modify the exhaust system of a motor vehicle in a manner that will amplify or increase the noise emitted by the motor of the vehicle above the maximum levels permitted under subsection (a) or violate the provisions of subsection (b). Headers and side exhausts are permitted provided the vehicle meets all the requirements of this section. (e) Fire equipment and racing vehicles. —This section does not apply to fire equipment or to racing vehicles being operated in an organized racing or competitive event conducted under a permit issued by local authorities.

Rhode Island

§ 31-23-13. Muffler Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke. No person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway. Any exhaust system shall be deemed defective if any changes, modifications, alterations, deletions, or adjustments have been made which would cause the exhaust system to generate a higher or louder sound level than would be generated by the exhaust system customarily installed by the manufacturer as original equipment. The defective exhaust system shall be replaced or repaired to restore the exhaust system to the performance specifications of the original equipment. Failure to replace or restore the exhaust system as required in this section within five (5) days shall be deemed a civil violation and violators are subject to fines enumerated in § 31-41.1-4.

South Carolina

§ 32-15-17. Exhaust system and muffler requirements — Class 2 misdemeanor No person may drive a motor vehicle on a highway unless the motor vehicle is equipped with an exhaust system and a muffler both in good working condition and in constant operation to prevent excessive or unusual noise. Exhaust systems on passenger or passenger-carrying vehicles used on any highway shall discharge the exhaust fumes at a location to the rear of the vehicle body or direct the exhaust fumes outward from the side of the vehicle body at a location rearward of any operable side windows. Any motor vehicle equipped with side exhaust according to the original vehicle manufacturer’s specifications is exempt from the location requirements. A bus used for the purpose of carrying school children may discharge the exhaust on the left side in front of the rear axle. Exhaust systems on property-carrying vehicles used on any highway shall discharge the exhaust fumes at a point rearward of the passenger-carrying compartment. No person may use a muffler cut-out on any motor vehicle upon a highway. A violation of this section is a Class 2 misdemeanor.

South Dakota

Tennessee

§ 55-9-202 Mufflers — Muffler cutouts prohibited — Penalty. (a) No person shall drive a motor vehicle on any road, street, or highway unless the motor vehicle is equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke. (b) It is unlawful to use a “muffler cutout” on any motor vehicle upon any road, street, or highway. (c) A violation of this section is a Class C misdemeanor.

Texas

§ 547.604. Muffler Required (a) A motor vehicle shall be equipped with a muffler in good working condition that continually operates to prevent excessive or unusual noise. (b) A person may not use a muffler cutout, bypass, or similar device on a motor vehicle.

Utah

§ 41-6a-1626. Mufflers — Prevention of noise, smoke, and fumes — Air pollution control devices (1) (a) A vehicle shall be equipped, maintained, and operated to prevent excessive or unusual noise. (b) A motor vehicle shall be equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation. (c) A person may not use a muffler cut-out, bypass, or similar device on a vehicle. (2) (a) Except while the engine is being warmed to the recommended operating temperature, the engine and power mechanism of a: (i) Gasoline-powered motor vehicle may not emit visible contaminants during operation; (ii) diesel engine manufactured on or after January 1, 1973, may not emit visible contaminants of a shade or density darker than 20% opacity; and (iii) diesel engine manufactured before January 1, 1973, may not emit visible contaminants of a shade or density darker than 40% opacity. (b) A person who violates the provisions of Subsection (2)(a) is guilty of a class C misdemeanor. (3) (a) A motor vehicle equipped by a manufacturer with air pollution control devices shall maintain the devices in good working order and in constant operation. (b) For purposes of the first sale of a vehicle at retail, an air pollution control device may be substituted for the manufacturer’s original device if the substituted device is at least as effective in the reduction of emissions from the vehicle motor as the air pollution control device furnished by the manufacturer of the vehicle as standard equipment for the same vehicle class. (c) A person who renders inoperable an air pollution control device on a motor vehicle is guilty of a class B misdemeanor. (4) Subsection (3) does not apply to a motor vehicle altered and modified to use clean fuel, as defined under Section 59-13-102, when the emissions from the modified or altered motor vehicle are at levels that comply with existing state or federal standards for the emission of pollutants from a motor vehicle of the same class.

Vermont

§ 1221. Condition of vehicle A motor vehicle, operated on any highway, shall be in good mechanical condition and shall be properly equipped.

Virginia

§ 46.2-1049. Exhaust system in good working order (1) No person shall drive and no owner of a vehicle shall permit or allow the operation of any such vehicle on a highway unless it is equipped with an exhaust system in good working order and in constant operation to prevent excessive or unusual levels of noise; provided however, that for motor vehicles, such exhaust system shall be of a type installed as standard factory equipment, or comparable to that designed for use on the particular vehicle as standard factory equipment. An exhaust system shall not be deemed to prevent excessive or unusual noise if it permits the escape of noise in excess of that permitted by the standard factory equipment exhaust system of private passenger motor vehicles or trucks of standard make. (2) The term “exhaust system,” as used in this section, means all the parts of a vehicle through which the exhaust passes after leaving the engine block, including mufflers and other sound-dissipative devices. (3) Chambered pipes are not an effective muffling device to prevent excessive or unusual noise, and any vehicle equipped with chambered pipes shall be deemed in violation of this section. (4) The provisions of this section shall not apply to (i) any antique motor vehicle licensed pursuant to § 46.2-730, provided that the engine is comparable to that designed as standard factory equipment for use on that particular vehicle, and the exhaust system is in good working order, or (ii) converted electric vehicles.

Washington

§ 46.37.390. Mufflers required — Smoke and air contaminant standards — Definitions — Penalty, exception (1) Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise, and no person shall use a muffler cut-out, bypass, or similar device upon a motor vehicle on a highway. (2) (a) No motor vehicle first sold and registered as a new motor vehicle on or after January 1, 1971, shall discharge into the atmosphere at elevations of less than three thousand feet any air contaminant for a period of more than ten seconds which is: (i) As dark as or darker than the shade designated as No. 1 on the Ringelmann chart, as published by the United States Bureau of Mines; or (ii) Of such opacity as to obscure an observer’s view to a degree equal to or greater than does smoke described in subsection (a)(i) above. (b) No motor vehicle first sold and registered prior to January 1, 1971, shall discharge into the atmosphere at elevations of less than three thousand feet any air contaminant for a period of more than ten seconds which is: (i) As dark as or darker than the shade designated as No. 2 on the Ringelmann chart, as published by the United States Bureau of Mines; or (ii) Of such opacity as to obscure an observer’s view to a degree equal to or greater than does smoke described in subsection (b)(i) above. (c) For the purposes of this subsection the following definitions shall apply: (i) “Opacity” means the degree to which an emission reduces the transmission of light and obscures the view of an object in the background; (ii) “Ringelmann chart” means the Ringelmann smoke chart with instructions for use as published by the United States Bureau of Mines in May 1967 and as thereafter amended, information circular 7718. (3) No person shall modify the exhaust system of a motor vehicle in a manner that will amplify or increase the noise emitted by the engine of such vehicle above that emitted by the muffler originally installed on the vehicle, and it shall be unlawful for any person to operate a motor vehicle not equipped as required by this subsection, or which has been amplified as prohibited by this subsection. A court may dismiss an infraction notice for a violation of this subsection if there is reasonable grounds to believe that the vehicle was not operated in violation of this subsection. This subsection (3) does not apply to vehicles twenty-five or more years old or to passenger vehicles being operated off the highways in an organized racing or competitive event conducted by a recognized sanctioning body. § 173-62-030 Standards. (1) No person shall operate any motor vehicle or any combination of such vehicles upon any public highway under any conditions of grade, load, acceleration, or deceleration in such a manner as to exceed the maximum permissible sound levels for the category of vehicle in Table I, as measured at a distance of 50 feet (15.2 meters) from the center of the lane of travel within the speed limits specified, under procedures established by the state commission on equipment in chapter 204-56 WAC, “procedures for measuring motor vehicle sound levels.” (2) Every motor vehicle operated upon the public highways shall at all times be equipped with an exhaust system and a muffler in good working order and constant operation to prevent excessive or unusual noise. (3) No person shall operate a motor vehicle in such a manner as to cause or allow to be emitted squealing, screeching, or other such noise from the tires in contact with the ground because of rapid acceleration or excessive speed around corners or other such reason, except that noise resulting from emergency braking to avoid imminent danger shall be exempt from this provision. (4) No person shall operate any motor vehicle upon any public highway if the vehicle exhaust system exceeds the maximum permissible sound levels of Table II for the category and year of vehicle, as measured at a distance of twenty inches (0.5 meters) from the exhaust outlet under procedures established by the state commission on equipment in chapter 204-56 WAC, “procedures for measuring motor vehicle sound levels.” (5) No person shall sell or offer for sale a NEW MOTOR VEHICLE except an off-highway vehicle, which produces a maximum noise exceeding the noise levels in Table III at a distance of 50 feet (15.2 meters) under acceleration test procedures established by the state commission on equipment in chapter 204-56 WAC, “procedures for measuring motor vehicle sound levels.”

West Virginia

§ 17C-15-34. Mufflers; prevention of noise, fumes, and smoke. (a) Every motor vehicle shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise. Such muffler shall be the muffler originally installed by the manufacturer of the vehicle or, if a replacement, the equivalent thereof. No person shall use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway. (b) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke.

Wisconsin

§ 347.39. Mufflers. (1) No person shall operate on a highway any motor vehicle subject to registration unless such motor vehicle is equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise or annoying smoke. This subsection also applies to motor bicycles. (2) No muffler or exhaust system on any vehicle mentioned in sub. (1) shall be equipped with a cutout, bypass, or similar device nor shall there be installed in the exhaust system of any such vehicle any device to ignite exhaust gases so as to produce flame within or without the exhaust system. No person shall modify the exhaust system of any such motor vehicle in a manner that will amplify or increase the noise emitted by the motor of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all the requirements of this section. (3) In this section, “muffler” means a device consisting of a series of chambers of baffle plates or other mechanical designs for receiving exhaust gases from an internal combustion engine and which is effective in reducing noise.

Wyoming

§ 31-5-953. Mufflers. (a) Every vehicle shall be equipped, maintained, and operated so as to prevent excessive or unusual noise. Every motor vehicle shall at all times be equipped with a muffler or other effective noise-suppressing system in good working order and in constant operation. No person shall use a muffler cut-out, bypass, or similar device. (b) The engine and power mechanism of every motor vehicle shall be so equipped and adjusted as to prevent the escape of excessive fumes or smoke. (c) This section applies to motorcycles, motor-driven cycles, multipurpose vehicles, and mopeds.