Q4 Does an aftermarket, replacement or modified tailpipe or muffler tip constitute a violation of Section 27151 VC?

No. Section 27151 VC prohibits the modification of exhaust systems to amplify or increase noise. The officer would have to establish that the modification increased the noise emitted by the vehicle by listening to the exhaust. In general, exhaust system piping, tubing, fittings, cosmetic tips or other passive devices placed behind the muffler have minimal impact on exhaust system sound levels.

Q5 Since Section 27150 requires that the muffler prevent excessive and unusual noise, can the driver of a vehicle be cited for violation of Section 2 7150 if it emits a sound different than the original factory installed muffler?

No. The prohibition against unusual noise refers to noises that are unusual for motor vehicles. Noise that may be unusual for a particular make or model of vehicle, but which is not necessarily unusual for other motor vehicles, should not be considered in violation, provided the noise is not excessive.

Q6 Aren't all modified exhaust systems unlawfuI under pollution control laws?

No. Current pollution control laws regarding aftermarket exhaust systems am quite complex, but do permit the installation of a variety of aftermarket and "exempt" systems. Due to the complexity of modem pollution control systems and the laws governing them, the CHP does not provide technical training in this area. Enforcement of pollution control laws is the responsibility of the Bureau of Automotive Repair through the "Smog Check" program.

Q7 What are the noise levels specified in Sections 27201-27206 VC? Can these be used to cite land vehicles?

No. Section 27200 VC prohibits the sale of now motor vehicles that exceed the noise limits specified in these Sections. The specified noise limits (80 dB(A) (decibels) for all new cars, pickup trucks, vans and motorcycles apply only to new motor vehicles, under fall throttle acceleration tests, measured 50 feet from the test vehicle, as specified in Sections 1040-1044, 1046 and 1047, Title 13, California Code of Regulations (13 CCR). These noise levels and the specified test methods apply to manufacturers and now car dealers only, for new vehicle certification purposes, and may not be used for enforcement purposes against vehicles being operated on public roadways. The CHP is not aware of any significant violation of Section 27200 VC by vehicle manufacturers or dealers.


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