ARTICLE 2. Exhaust Systems [27150. - 27159.]

Cal. Vehicle Code - VEH 2.

in effect

Cal. Vehicle Code - VEH § 27150. Section 27150.

(a) Every motor vehicle equipped with an internal combustion engine and subject to registration 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 muffler or exhaust system shall be equipped with a cutout, bypass, or similar device. (b) Except as provided in Division 16.5 (commencing with Section 38000) with respect to off-highway motor vehicles subject to identification, every passenger vehicle operated off the highways shall at all times be equipped with an adequate muffler in constant operation and properly maintained so as to meet the requirements of Article 2.5 (commencing with Section 27200), and no muffler or exhaust system shall be equipped with a cutout, bypass, or similar device. (c) The provisions of subdivision (b) shall not be applicable to passenger vehicles being operated off the highways in an organized racing or competitive event conducted under the auspices of a recognized sanctioning body or by permit issued by the local governmental authority having jurisdiction, or to vehicles not equipped with an internal combustion engine.

Cal. Vehicle Code - VEH § 27150.1. Section 27150.1.

No person engaged in a business that involves the selling of motor vehicle exhaust systems, or parts thereof, including, but not limited to, mufflers, shall offer for sale, sell, or install, a motor vehicle exhaust system, or part thereof, including, but not limited to, a muffler, unless it meets the regulations and standards applicable pursuant to this article. Motor vehicle exhaust systems or parts thereof include, but are not limited to, nonoriginal exhaust equipment. A violation of this section is a misdemeanor.

Cal. Vehicle Code - VEH § 27150.2. Section 27150.2.

(a) Stations providing referee functions pursuant to Section 44036 of the Health and Safety Code shall provide for the testing of vehicular exhaust systems and the issuance of certificates of compliance only for those vehicles that have received a citation for a violation of Section 27150 or 27151. (b) A certificate of compliance for a vehicular exhaust system shall be issued pursuant to subdivision (a) if the vehicle complies with Sections 27150 and 27151. Exhaust systems installed on motor vehicles, other than motorcycles, with a manufacturer’s gross vehicle weight rating of less than 6,000 pounds comply with Sections 27150 and 27151 if they emit no more than 95 dbA when tested in accordance with the most current SAE International standard. (c) An exhaust system certificate of compliance issued pursuant to subdivision (a) shall identify, to the extent possible, the make, model, year, license number, and vehicle identification number of the vehicle tested, and the make and model of the exhaust system installed on the vehicle. (d) The station shall charge a fee for the exhaust system certificate of compliance issued pursuant to subdivision (a). The fee charged shall be calculated to recover the costs incurred by the Department of Consumer Affairs to implement this section. The fees charged by the station shall be deposited in the Vehicle Inspection and Repair Fund established by Section 44062 of the Health and Safety Code. (e) Vehicular exhaust systems are exempt from the requirements of Sections 27150 and 27151 if compliance with those sections, or the regulations adopted pursuant thereto, would cause an unreasonable hardship without resulting in a sufficient corresponding benefit with respect to noise level control. (f) This section shall remain in effect only until January 1, 2027, and as of that date is repealed.

Cal. Vehicle Code - VEH § 27150.3. Section 27150.3.

(a) A person may not modify the exhaust system of a motor vehicle with a whistle-tip. (b) A person may not operate a motor vehicle if that vehicle’s exhaust system is modified in violation of subdivision (a). (c) A person may not engage in the business of installing a whistle-tip onto a motor vehicle’s exhaust system. (d) For purposes of subdivisions (a) and (c), a “whistle-tip” is a device that is applied to, or is a modification of, a motor vehicle’s exhaust pipe for the sole purpose of creating a high-pitched or shrieking noise when the motor vehicle is operated.

Cal. Vehicle Code - VEH § 27150.4. Section 27150.4.

(a) The Department of the California Highway Patrol shall evaluate the efficacy of sound-activated enforcement devices by evaluating devices from at least three different companies. (b) (1) On or before January 1, 2025, the department shall prepare and submit its findings and recommendations from the evaluation in a report to the Legislature, which shall include all of the following information: (A) How effective the devices are at determining that a vehicle was not equipped with an adequate muffler in constant operation and properly maintained in accordance with the requirements of Article 2.5 (commencing with Section 27200). (B) How often the device identified a potential violation that was not related to a violation of Section 27150, and the types of sounds other than a loud muffler that triggered the device. (C) What percentage of time an officer was unable to determine the source of the sound that activated the device. (D) How often the device was required to be serviced. (E) What, if any, technology does the sound-activated enforcement system use to determine the direction or source of the sound that violated the sound limits provided for in Article 2.5 (commencing with Section 27200). (F) Where the devices were located, and whether the location had any consequences to the effectiveness of the device. (G) The number of devices the department tested and from which companies were the devices that were tested. (H) Recommendations on all of the following: (i) Which, if any, device or devices would the department recommend be used for the purposes of enforcing Sections 27150 and 27151, and the reasons for that determination. If the department determines that it does not recommend any of the devices tested, the report shall include the standards and parameters that shall be met by future technology. (ii) What, if any, restrictions should be placed on the use of sound-activated enforcement devices in enforcing Sections 27150 and 27151, including, but not limited to, the decibel level setting for triggering a potential violation for the purposes of enforcement. (iii) Where the devices should be optimally located in order to reduce the chances of a false violation. (iv) Descriptions and explanation of any necessary and associated training that an individual reviewing these violations would need to go through in order to operate the device, including recommendations for what is necessary for a robust human review process. (v) Any other recommendations the department believes would be necessary for authorizing the use of sound-activated enforcement devices. (I) A video demonstrating the device. The video shall be edited to remove any personally identifying information, including the blurring of persons recorded in the video, street addresses, and license plates. (2) The report required by this subdivision shall be submitted in compliance with Section 9795 of the Government Code. (c) The department shall delete all videos recorded on a highway by a device within five days of the video being recorded. However, the department shall keep 15 videos from the devices of each company evaluated for the purposes of preparing the report required by this section and documenting the issues related to each device that helped the department make its recommendations. The department shall not keep any recording that picked up audio of a person speaking, if recorded on a highway. (d) Notwithstanding Division 10 (commencing with Section 7920.000) of Title 1 of the Government Code, or any other law, information collected and maintained by the department using a sound-activated enforcement device that could be used to identify the identity or location of any individual shall be confidential and only be used for purposes of this section, and shall not be disclosed to any other persons, including, but not limited to, any other state or federal government agency or official for any other purpose, except as required by the reporting requirements in this section, state or federal law, court order, or in response to a subpoena in an individual case or proceeding. (e) For purposes of this section, “sound-activated enforcement device” or “device” means an electronic device that utilizes automated equipment that activates when the noise levels have exceeded the legal sound limit established in Section 27151 and is designed to obtain clear video of a vehicle and its license plate. A sound-activated enforcement device shall do all of the following: (1) Record audio, precision accuracy noise levels, and high definition video in two directions. (2) Utilize an automated system that triggers when excessive vehicle noise over the limit is detected and save the data for review. (3) Automatically delete any evidence not related to a violation. (4) Permit the department to manually review evidence to ensure a violation has occurred. (5) Conform to the class 1 accuracy standards in the International Electrotechnical Commission’s (IEC) standard IEC 61672:2013, or any other accuracy standard determined to be appropriate by the department.

Cal. Vehicle Code - VEH § 27150.5. Section 27150.5.

Any person holding a retail seller’s permit who sells or installs an exhaust system, or part thereof, including, but not limited to, a muffler, in violation of Section 27150.1 or 27150.2 or the regulations adopted pursuant thereto, shall thereafter be required to install an exhaust system, or part thereof, including, but not limited to, a muffler, which is in compliance with such regulations upon demand of the purchaser or registered owner of the vehicle concerned, or to reimburse the purchaser or registered owner for the expense of replacement and installation of an exhaust system, or part thereof, including, but not limited to, a muffler, which is in compliance, at the election of such purchaser or registered owner.

Cal. Vehicle Code - VEH § 27150.7. Section 27150.7.

A court may dismiss any action in which a person is prosecuted for operating a vehicle in violation of Section 27150 or 27151 if a certificate of compliance has been issued by a station pursuant to Section 27150.2, or if the defendant had reasonable grounds to believe that the exhaust system was in good working order and had reasonable grounds to believe that the vehicle was not operated in violation of Section 27150 or 27151.

Cal. Vehicle Code - VEH § 27151. Section 27151.

(a) A person shall not modify the exhaust system of a motor vehicle in a manner which 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). A person shall not 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 less than 6,000 pounds, other than motorcycles, a sound level of 95 dbA or less, when tested in accordance with the most current SAE International standard, complies with this section. Motor vehicle exhaust systems or parts thereof include, but are not limited to, nonoriginal exhaust equipment.

Cal. Vehicle Code - VEH § 27151.1. Section 27151.1.

(a) For a violation of Section 27150.3 or 27151 of a vehicle under 14,000 pounds gross vehicle weight rating, a court shall require a certificate of compliance for a vehicular exhaust system in compliance with subdivision (b) of Section 27150.2. A court shall utilize the notification procedures set forth in Section 40002. If a certificate of compliance is not provided to the court within three months of the violation date, the court shall treat this failure as noncompliance pursuant to subdivision (c) of Section 40002 and follow the provisions of Section 40002.1 to inform the Department of Motor Vehicles. (b) The department shall, before renewing the registration of any vehicle, check to see whether the court has issued a hold on the vehicle registration for a violation of Section 27150.3 or 27151, and shall refuse to renew the registration until it has received a notification from the court that a certificate of compliance has been issued. (c) This section shall become operative on January 1, 2027.

Cal. Vehicle Code - VEH § 27152. Section 27152.

The exhaust gases from a motor vehicle shall not be directed to the side of the vehicle between 2 feet and 11 feet above the ground.

Cal. Vehicle Code - VEH § 27153. Section 27153.

(a) A motor vehicle shall not be operated in a manner resulting in the escape of excessive smoke, flame, gas, oil, or fuel residue. (b) A nongasoline heavy-duty onroad motor vehicle with a gross vehicle weight rating of more than 14,000 pounds shall not be operated in a manner resulting in the escape of visible smoke, except during active regeneration. (c) (1) A violation of this section is a correctable violation pursuant to Article 4 (commencing with Section 40610) of Chapter 2 of Division 17. Except as provided in paragraph (2) and subdivision (d), an owner or operator of a vehicle found to be in violation of this section shall have 45 days to correct the violation and the vehicle shall not be prohibited from being used during this time. (2) Except as provided in subdivision (d), an owner or operator of a vehicle that is used exclusively in the conduct of agricultural operations and that is found to be in violation of this section shall have a time period determined by the State Air Resources Board that is not less than 75 days from the date of the citation to correct the violation and the vehicle shall not be prohibited from being used during that time. (d) Notwithstanding subdivision (c), a vehicle found to have willfully tampered emission controls, including the vehicle’s onboard diagnostics system, shall not be operated. (e) This section applies to motor vehicles of the United States or its agencies, to the extent authorized by federal law.

Cal. Vehicle Code - VEH § 27153.5. Section 27153.5.

(a) No motor vehicle first sold or registered as a new motor vehicle on or after January 1, 1971, shall discharge into the atmosphere at elevation of less than 4,000 feet any air contaminant for a period of more than 10 seconds which is: (1) As dark or darker in shade as that designated as No. 1 on the Ringelmann Chart, as published by the United States Bureau of Mines, or (2) Of such opacity as to obscure an observer’s view to a degree equal to or greater than does smoke described in paragraph (1) of this subdivision. (b) No motor vehicle first sold or registered prior to January 1, 1971, shall discharge into the atmosphere at elevation of less than 4,000 feet any air contaminant for a period of more than 10 seconds which is: (1) As dark or darker in shade than that designated as No. 2 on the Ringelmann Chart, as published by the United States Bureau of Mines, or (2) Of such opacity as to obscure an observer’s view to a degree equal to or greater than does smoke described in paragraph (1) of this subdivision. (c) The provisions of this section apply to motor vehicles of the United States or its agencies, to the extent authorized by federal law.

Cal. Vehicle Code - VEH § 27154. Section 27154.

The cab of any motor vehicle shall be reasonably tight against the penetration of gases and fumes from the engine or exhaust system. The exhaust system, including the manifold, muffler, and exhaust pipes shall be so constructed as to be capable of being maintained and shall be maintained in a reasonably gastight condition.

Cal. Vehicle Code - VEH § 27154.1. Section 27154.1.

(a) The flooring in all motor vehicles shall be substantially constructed, free of unnecessary holes and openings and shall be maintained so as to minimize the entrance of fumes, exhaust gases, or fire. (b) Floors shall not be permeated with oil or other substances likely to cause injury to persons using the floor as a traction surface.

Cal. Vehicle Code - VEH § 27155. Section 27155.

No motor vehicle shall be operated or parked upon any highway unless the filling spout for the fuel tank is closed by a cap or cover of noncombustible material.

Cal. Vehicle Code - VEH § 27156. Section 27156.

(a) No person shall operate or leave standing upon a highway a motor vehicle that is a gross polluter, as defined in Section 39032.5 of the Health and Safety Code. (b) No person shall operate or leave standing upon a highway a motor vehicle that is required to be equipped with a motor vehicle pollution control device under Part 5 (commencing with Section 43000) of Division 26 of the Health and Safety Code or any other certified motor vehicle pollution control device required by any other state law or any rule or regulation adopted pursuant to that law, or required to be equipped with a motor vehicle pollution control device pursuant to the National Emission Standards Act (42 U.S.C. Secs. 7521 to 7550, inclusive) and the standards and regulations adopted pursuant to that federal act, unless the motor vehicle is equipped with the required motor vehicle pollution control device that is correctly installed and in operating condition. No person shall disconnect, modify, or alter any such required device. (c) No person shall install, sell, offer for sale, or advertise any device, apparatus, or mechanism intended for use with, or as a part of, a required motor vehicle pollution control device or system that alters or modifies the original design or performance of the motor vehicle pollution control device or system. (d) If the court finds that a person has willfully violated this section, the court shall impose the maximum fine that may be imposed in the case, and no part of the fine may be suspended. (e) “Willfully,” as used in this section, has the same meaning as the meaning of that word prescribed in Section 7 of the Penal Code. (f) No person shall operate a vehicle after notice by a traffic officer that the vehicle is not equipped with the required certified motor vehicle pollution control device correctly installed in operating condition, except as may be necessary to return the vehicle to the residence or place of business of the owner or driver or to a garage, until the vehicle has been properly equipped with such a device. (g) The notice to appear issued or complaint filed for a violation of this section shall require that the person to whom the notice to appear is issued, or against whom the complaint is filed, produce proof of correction pursuant to Section 40150 or proof of exemption pursuant to Section 4000.1 or 4000.2. (h) This section shall not apply to an alteration, modification, or modifying device, apparatus, or mechanism found by resolution of the State Air Resources Board to do either of the following: (1) Not to reduce the effectiveness of a required motor vehicle pollution control device. (2) To result in emissions from the modified or altered vehicle that are at levels that comply with existing state or federal standards for that model-year of the vehicle being modified or converted. (i) Aftermarket and performance parts with valid State Air Resources Board Executive Orders may be sold and installed concurrent with a motorcycle’s transfer to an ultimate purchaser. (j) This section applies to motor vehicles of the United States or its agencies, to the extent authorized by federal law.

Cal. Vehicle Code - VEH § 27156.1. Section 27156.1.

The installation, prior to January 1, 1974, of an auxiliary gasoline fuel tank for use on a 1973 or earlier model year motor vehicle, which vehicle is required, pursuant to Part 5 (commencing with Section 43000) of Division 26 of the Health and Safety Code or the National Emission Standards Act (42 U.S.C., Secs. 1857f-1 to 1857f-7, inclusive), to be equipped with a fuel system evaporative loss control device, shall not be deemed a violation of Section 27156 of this code. As used in this section, the term “auxiliary gasoline fuel tank,” has the same meaning as defined in subdivision (b) of Section 43834 of the Health and Safety Code.

Cal. Vehicle Code - VEH § 27156.2. Section 27156.2.

Notwithstanding any other provision of law, any publicly owned authorized emergency vehicle operated by a peace officer, as defined in Section 830 of the Penal Code, any authorized emergency vehicle, as defined in Section 165 and used for fighting fires or responding to emergency fire calls pursuant to paragraph (2) of subdivision (b) or pursuant to subdivision (c) or (d) of that section, and any publicly owned authorized emergency vehicle used by an emergency medical technician-paramedic, as defined in Section 1797.84 of the Health and Safety Code, is exempt from requirements imposed pursuant to California law and the regulations adopted pursuant thereto for motor vehicle pollution control devices.

Cal. Vehicle Code - VEH § 27156.3. Section 27156.3.

Notwithstanding any other provision of law, any motor vehicle of mosquito abatement, vector control, or pest abatement districts or agencies, any authorized emergency vehicle as defined in Section 165, except subdivision (f) thereof, and any ambulance used by a private entity under contract with a public agency, is exempt from requirements imposed pursuant to California law and the regulations adopted pursuant thereto for motor vehicle pollution control devices.

Cal. Vehicle Code - VEH § 27157. Section 27157.

The State Air Resources Board, after consultation with, and pursuant to the recommendations of, the commissioner, shall adopt such reasonable regulations as it determines are necessary for the public health and safety regarding the maximum allowable emissions of pollutants from vehicles upon a highway. Such regulations shall apply only to vehicles required by Part 5 (commencing with Section 43000) of Division 26 of the Health and Safety Code or any federal law or regulation to be equipped with devices or systems to control emission of pollutants from the exhaust and shall not be stricter than the emission standards required of that model year motor vehicle when first manufactured.

Cal. Vehicle Code - VEH § 27157.5. Section 27157.5.

The State Air Resources Board, after consultation with, and pursuant to the recommendations of, the commissioner, shall adopt such reasonable standards as it determines are necessary for the public health and safety for the emission of air pollutants from the exhaust of motor vehicles of 1955 through 1965 model years. These standards shall be based on the normal emissions of such cars when the timing and carburetor are in proper adjustment and the spark plugs are in proper operating condition.

Cal. Vehicle Code - VEH § 27158. Section 27158.

After notice by a traffic officer that a vehicle does not comply with any regulation adopted pursuant to Section 27157, no person shall operate, and no owner shall permit the operation of, such vehicle for more than 30 days thereafter unless a certificate of compliance has been issued for such vehicle in accordance with the provisions of Section 9889.18 of the Business and Professions Code or unless the department has checked the vehicle and determined that the vehicle has been made to comply with such regulation adopted pursuant to Section 27157. A certificate of compliance issued for such vehicle shall, for a period of one year from date of issue, constitute proof of compliance with any regulations adopted pursuant to Section 27157 provided that no required pollution control device has been disconnected, modified, or altered or has been adjusted by other than a licensed installer in a licensed motor vehicle pollution control device installation and inspection station subsequent to the issuance of the certificate of compliance. The provisions of this section shall apply to the United States and its agencies to the extent authorized by federal law.

Cal. Vehicle Code - VEH § 27158.1. Section 27158.1.

(a) Commencing one year after the effective date of a regulation implementing the Heavy-Duty Vehicle Inspection and Maintenance Program (Chapter 5.5 (commencing with Section 44150) of Part 5 of Division 26 of the Health and Safety Code), a legal owner or registered owner of a nongasoline heavy-duty onroad motor vehicle with a gross vehicle weight rating of more than 14,000 pounds shall maintain a Heavy-Duty Vehicle Inspection and Maintenance Compliance Certificate, as described in Section 44152 of the Health and Safety Code, or a facsimile or electronic copy of that certificate of compliance, with the vehicle for which the certificate is issued. (b) Subdivision (a) does not apply when a Heavy-Duty Vehicle Inspection and Maintenance Compliance Certificate is necessarily removed from the vehicle for the purpose of renewal or when the vehicle is left unattended. (c) A violation of this section shall be cited in accordance with Section 40610.

Cal. Vehicle Code - VEH § 27158.2. Section 27158.2.

(a) The driver of a nongasoline heavy-duty onroad motor vehicle with a gross vehicle weight rating of more than 14,000 pounds shall present a Heavy-Duty Vehicle Inspection and Maintenance Compliance Certificate, as described in Section 44152 of the Health and Safety Code, or other evidence of that certificate of compliance, of the vehicle under the driver’s immediate control for examination upon demand by any peace officer. (b) The driver of the vehicle described in subdivision (a) shall not present to any peace officer a Heavy-Duty Vehicle Inspection and Maintenance Compliance Certificate not issued for that vehicle.

Cal. Vehicle Code - VEH § 27158.5. Section 27158.5.

After notice by a traffic officer that a motor vehicle does not comply with any standard adopted pursuant to Section 27157.5, no person shall operate, and no owner shall permit the operation of, such motor vehicle for more than 30 days thereafter unless a certificate of compliance has been issued for such vehicle in accordance with the provisions of Section 9889.18 of the Business and Professions Code or unless the department has checked the vehicle and determined that the vehicle has been made to comply with such standard adopted pursuant to Section 27157.5. A certificate of compliance issued for such vehicle shall, for a period of one year from date of issue, constitute proof of compliance with the standards determined pursuant to Section 27157.5.

Cal. Vehicle Code - VEH § 27159. Section 27159.

Any uniformed member of the California Highway Patrol may order a vehicle stored when it is located within the territorial limits in which the member may act if requested by a representative of the State Air Resources Board to remove the vehicle from service pursuant to subdivision (f) of Section 44011.6 of the Health and Safety Code. All towing and storage fees for a vehicle removed under this section shall be paid by the owner.

Source: CA Legislative Counsel Bulk DataURL: https://downloads.leginfo.legislature.ca.gov/pubinfo_2025.zipFetched: 6/27/2026