Q11 What happened to the Muffler Certification and the Licensed Muffler Certification Station Programs?

Funding for both programs was terminated in 1979. There are currently no Official Muffler Certification Stations, no listing of certified mufflers and no formal mechanism in place to conduct objective vehicle or exhaust noise testing.

Q12 Can local authorities enact or enforce more strict ordinances regarding vehicle noise?

No. Section 21 VC makes the VC applicable and uniform throughout the state, and prohibits local authorities from enacting or enforcing any ordinance on the matters covered by the VC unless expressly authorized to do so. In-use vehicle noise is addressed in Sections 23130 and 23130.5 VC. There Is no provision in the VC that permits local authorities to adopt additional noise limitations. Consequently, citations issued under such ordinances are invalid.

Q13 Some aftermarket exhaust systems include documentation that the system has been tested and found to meet the requirements of Section 1036(d)(1), 13 CCR. Are those legal?

The CHP does not have the resources to independently verify manufacturer's claims, but is aware that some aftermarket exhaust systems do meet the noise levels specified in Section 1036(d)(1), 13 CCR. An officer may consider such documentation in evaluating an exhaust system for excessive noise, both during the issuance of a citation and when clearing a citation pursuant to Section 40610(b) VC.

Q14 What type of enforcement action should be taken against vehicles emitting excessive noise?

Providing none of the disqualifying conditions listed in Section 40610(b) are present, the use of the CHP 281, "Notice to Correct," or checking the Dismissable Violation "Yes" box on the CHP 215, "Notice to Appear (Arrest Citation)," would be appropriate for these violations.


Knox Letter | CHP Bulletin | Attachment 1 2 3 4
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