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

For vehicle and motorcycle noise, the County of Shasta (California) relies on California state law rather than a unique county decibel ordinance, because the State largely controls in-use vehicle noise. California Vehicle Code Section 27150 requires every motor vehicle to be equipped with an adequate muffler in constant operation and properly maintained to prevent excessive or unusual noise, and prohibits cutouts, bypasses, or similar devices. Section 27151 prohibits modifying a vehicle's exhaust system to amplify or increase noise, and establishes that passenger vehicles and light trucks under 6,000 pounds (other than motorcycles) comply if they emit no more than 95 dBA when tested under Society of Automotive Engineers Standard J1492. California Vehicle Code Section 23130 sets in-use noise limits for vehicles operating on the highway under varying speeds and weights. These provisions are enforced by the Shasta County Sheriff's Office and the California Highway Patrol on roads in the unincorporated area, typically by citation. Stationary vehicle noise on private property - for example a neighbor repeatedly revving an engine or running loud equipment - can additionally be treated as a nuisance under County Code Chapter 8.28 or a disturbance under California Penal Code Section 415.