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VEHICLE CODE
SECTION 27150-27159

27150. (a) Every motor vehicle 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.

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.

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 Society of Automotive Engineers Standard J1169 May 1998.
(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.

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.

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.

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.

27151. (a) 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 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 less
than 6,000 pounds, other than motorcycles, a sound level of 95 dbA or
less, when tested in accordance with 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.

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.

27153. No motor vehicle shall be operated in a manner resulting in
the escape of excessive smoke, flame, gas, oil, or fuel residue.
The provisions of this section apply to motor vehicles of the
United States or its agencies, to the extent authorized by federal
law.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.