Boise, ID Noise Ordinances: Vehicle Noise (2026)

Muffler Required: Every motor vehicle operated within the City limits shall at all times be equipped with a muffler in good working order and in constant operation to prevent excessive noise and smoke.

B.   Noise Suppressing System: When any motor vehicle was originally equipped with a noise suppressing system or when any motor vehicle is required by law or regulation of this State or the Federal government to have a noise suppressing system, that system shall be maintained in good working order.

C.   Prohibitions: No person or owner shall:

1.   Operate or cause or permit to be operated a motor vehicle with a disconnected muffler system, or an exhaust or sound suppression system in disrepair.

2.   Modify or alter a motor vehicle's muffler system or its operation in any manner, except to conform to the manufacturer's specifications.

3.   Operate or cause or permit to be operated a motor vehicle with a muffler cutout, bypass or similar device engaged when that device is designed to divert exhaust noise away from a muffler or other noise suppressing system with the intent of amplifying or increasing noise. Whether operated manually or electronically, the device shall always remain in the closed position while the vehicle is in operation upon public streets or highways.

4.   Modify the exhaust system of a motor vehicle in a manner which amplifies or increases the noise of the motor vehicle above that emitted by the