Exhaust Modified to Be Louder
A CVC 27151 citation means the exhaust system was modified so that it amplifies or increases the engine noise beyond what Vehicle Code 27150 or the noise limits allow (Vehicle Code 27151(a)). An exhaust that is loud because it is worn, not modified, falls under 27150 instead. Until January 1, 2027, a 27151(a) violation on a motorcycle cannot be issued as a fix-it ticket (Vehicle Code 40610(b)(4)). Restoring a compliant exhaust, then getting the correction certified, resolves this violation.
Correction Window
The deadline is printed on your citation. Restore the exhaust to a compliant system and certify before that date.
Fee After Correction
These steps apply when your ticket was issued as correctable. An officer does not issue it that way if there is evidence of fraud or persistent neglect, the violation presents an immediate safety hazard, or you cannot promptly correct it (Vehicle Code 40610(b)). When the court accepts your proof of correction, the court clerk collects a $25 fee for each corrected violation (Vehicle Code 40611). There is no fee if the agency that cited you handles the correction and nothing is sent to the court (Vehicle Code 40611(c)). Without proof of correction, you may owe the full fine. Check your notice or ask your court for the amount.
Who Can Certify
A police department, the CHP, a sheriff, a marshal or another agency that enforces the Vehicle Code can certify this correction. The Smog Check Referee, a Bureau of Automotive Repair (BAR) contractor, can also test the exhaust noise of a vehicle cited under CVC 27151 and issue a certificate if it passes. The Referee notes that this certificate may not clear the violation by itself; the court decides.
The court must dismiss a corrected violation when you deliver proof of correction on or before the date on your ticket (Vehicle Code 40522). After that date it may not accept the correction, and you may owe the full fine. If you fail to appear without good cause, the court may add a civil assessment of up to $100 after mailing you a warning notice (Penal Code 1214.1). Willfully failing to appear, or willfully failing to deliver proof of correction, is a misdemeanor (Vehicle Code 40508 and 40616). If you need more time, ask the court before the date passes.
Step by Step
How to Correct This Violation
- 1
Have an exhaust repair shop assess the current exhaust system and identify what modifications are non-compliant.
- 2
Replace the non-compliant exhaust components with California-compliant parts.
- 3
Confirm the exhaust noise level meets the legal standard.
- 4
Have a law enforcement officer sign the certificate of correction. You can also get a Smog Check Referee noise certificate, but the Referee says a certificate may not clear the violation by itself, so ask the court what it accepts.
- 5
Submit the signed citation and $25 fee to the court before your deadline.
Questions
Frequently Asked Questions
- What is the maximum exhaust noise level allowed in California?
- For vehicles under 6,000 pounds gross vehicle weight rating, other than motorcycles, CVC 27151(b) says an exhaust that tests at 95 dBA or less complies. The Smog Check Referee can test a vehicle cited under CVC 27151; it does not test vehicles over 5,999 pounds, so contact the court in that case.
This guide covers passenger vehicles. Some rules differ for commercial vehicles and truck tractors (for example, where registration tabs go under Vehicle Code 5204(a)). If you were driving one, check with your employer or a licensed attorney.
This guide provides general procedural information only. It is not legal advice. For questions specific to your citation, contact the court listed on your ticket.
Also have a moving violation on your ticket?
Speeding and moving violations follow a different process. TicketClear prepares your written declaration.
See how TicketClear worksYour ticket has a deadline. Tell your side today.
Most California citations have a 60-day deadline. Write what happened in your own words, then review, edit and sign your declaration.
Start my declarationFree to start · $49.99 when you're ready to download