Napa, CA Noise Ordinances: Vehicle Noise (2026)

California has occupied the field on in-use vehicle noise standards, so the City of Napa does not maintain a separate vehicle-noise chapter. CVC 27150 requires every motor vehicle to be equipped at all times with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise. CVC 27151 bars modifying a vehicle's exhaust system to amplify or increase noise above the limits in CVC 27200-27207 or above 95 dB(A) measured under SAE Standard J1169. AB 1824, effective January 1, 2019, eliminated the prior fix-it ticket option and made loud-exhaust citations subject to immediate fines. Napa Police enforce both sections on city streets. Stationary vehicle audio - for example, a parked car playing music in a driveway - that is audible outside the building can also be reached under NMC 8.08.010 (loudspeaker or amplification system audible outside a building) and through California Penal Code 415(2). Ice-cream vending vehicles are subject to the seasonal amplified-music windows in NMC 8.08.020(B).