Vacaville, CA Noise Ordinances: Vehicle Noise (2026)

California vehicle exhaust and noise rules are statewide. Vehicle Code §27150 requires that every motor vehicle be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise, and prohibits muffler cutouts, bypasses, and similar devices. §27151 prohibits modifying the exhaust system to amplify or increase the noise emitted by the motor; CHP enforces against passenger vehicles by reference to SAE J1169, with 95 dB(A) as the standard limit for passenger cars and light trucks. Vacaville Police enforce CVC §§27150-27151 on city streets. For vehicle noise that happens off the roadway - revving in a driveway, loud car stereos at a residence, idling delivery trucks at a loading dock - Vacaville Municipal Code Chapter 8.10 applies, treating noise that disturbs a reasonable person of normal sensitivity as a public nuisance, and the construction/commercial-equipment time windows in Chapter 8.10 (10:00 p.m. - 6:00 a.m. weekdays, 10:00 p.m. - 8:00 a.m. Sundays) constrain certain operations within 500 feet of an occupied residence. California Vehicle Code §23130 sets statewide on-roadway noise limits for vehicles in motion. Diesel idling on private property is also separately limited by CARB's statewide truck-idling rule.