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

Lake County does not have its own roadway vehicle-noise ordinance; motor-vehicle noise on public highways is preempted by the California Vehicle Code and enforced statewide. Vehicle Code Section 27150 requires that every motor vehicle be equipped at all times with an adequate muffler in constant operation and properly maintained to prevent excessive or unusual noise, and prohibits mufflers or exhaust systems with a cutout, bypass, or similar device. Section 27151 makes it unlawful to modify a vehicle's exhaust system in a way that amplifies or increases the noise so the vehicle no longer complies with Section 27150 or exceeds the noise limits set in the Vehicle Code. These statutes are enforced by the Lake County Sheriff and the California Highway Patrol. Off-road and stationary vehicle noise on private property (for example, idling or revving in a yard) is not covered by the Vehicle Code in the same way and can instead be addressed under the County Zoning Code Performance Standards (Section 41.11 property-line limits) or as a loud-or-unusual-noise public nuisance under Chapter 13. The County's noise standards do exempt aircraft and agricultural equipment, but on-road vehicle noise specifically defers to state law.