Lakewood, CO Noise Ordinances: Vehicle Noise (2026)

Section 9.52.090, 'Exhausts, Mufflers,' makes it unlawful to discharge into the open air the exhaust of any steam engine, stationary internal combustion engine, air compressor equipment, motorboat, motor vehicle or other power device which is not equipped with an adequate muffler in constant operation and properly maintained to prevent any unreasonable noise, and separately bars modifying or using such muffler or exhaust system with a cutoff, bypass or similar device, which reaches aftermarket exhaust cutouts and straight-pipe modifications. Section 9.52.120 adds a companion rule for engine (dynamic) braking: no person shall operate any motor vehicle with a dynamic braking device engaged which is not properly muffled. Section 9.52.030 defines a dynamic braking device as one that converts a truck's engine 'from an internal combustion engine to an air compressor for the purpose of braking without the use of wheel brakes,' commonly known as a Jake brake. Neither section sets a decibel limit; both key on whether the muffler or exhaust system is adequate, in constant operation and properly maintained.

A separate provision, § 9.52.100, 'Defect in vehicle or load,' independently bars operating a vehicle so out of repair, so loaded or in such a manner as to cause any unreasonable noise, which reaches rattling loads and worn suspension parts as well as exhaust noise. All three sections sit inside Chapter 9.52's non-exclusive list of acts declared unreasonable noise under § 9.52.050, and each runs continuously rather than during defined hours.