Amador County, CA Noise Ordinances: Vehicle Noise (2026)

Amador County's public nuisance noise ordinance (Chapter 9.44) does not contain vehicle-specific decibel limits or muffler rules, so motor-vehicle noise on public roads in the unincorporated county is primarily controlled by the California Vehicle Code, enforced by the Sheriff and CHP. Vehicle Code section 27150 requires every motor vehicle to be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise, and prohibits cutouts or bypass devices. Section 27151 bars modifying an exhaust system to amplify or increase noise beyond legal limits; for vehicles under 6,000 pounds GVWR (other than motorcycles), a sound level of 95 dBA or less, tested to the applicable SAE standard, complies. Section 27007 prohibits operating a sound amplification system that can be heard outside the vehicle from 50 or more feet while the vehicle is being operated on a highway, subject to limited exceptions. Loud car stereos, modified exhausts, and engine revving are therefore addressed by these statewide rules. In addition, vehicle noise on private property or at residences and event venues can still be cited under the county's general nuisance noise ordinance if it is disturbing, excessive, or offensive, including during the 10 p.m.–7 a.m. prima facie window.