Waukegan, IL Noise Ordinances: Vehicle Noise (2026)

Sec. 11-31 of the Waukegan City Code requires an adequate muffler, in constant operation and properly maintained, on any steam engine, stationary internal combustion engine, air compressor equipment, motorboat, motor vehicle, or other power device before its exhaust can be discharged into the open air, and the muffler has to be there specifically to prevent unnecessary noise, not just to exist. The section separately bars modifying or using any muffler or exhaust system with a cutout, bypass, or similar device, closing off the common workaround of installing a switch that routes exhaust around the muffler for a louder sound on demand.

This muffler mandate traces to the 1974 code and sits in Article II of chapter 11, the city's noise control article, just ahead of Sec. 11-32's numeric decibel table and Sec. 11-33's separate 80 dBA cap on light motor vehicles. Because a defective or removed muffler is also one of the named triggers for the excessive-noise test in Sec. 11-33(b), which lets an officer administer a stationary noise test at a driver's request, a Sec. 11-31 violation and an excessive-noise citation can arise from the same loud exhaust. Chapter 11's own general penalty section, Sec. 00 for a first offense, with each day of continued violation charged as a separate offense.