Exhaust Noise in Colorado
Colorado sets no statewide decibel limit for passenger cars. A muffler in good working order is required, exhaust may not produce excessive or unusual noise, and cutouts or bypasses are prohibited.
Verified against primary sources · August 2026
What the law says
Colorado law is qualitative rather than numeric: A muffler in good working order is required, exhaust may not produce excessive or unusual noise, and cutouts or bypasses are prohibited. Modifications louder than stock are specifically prohibited; commercial vehicles over 10,000 lb have a separate compression-brake muffler rule.
Specific Limits
- Statewide decibel limit
- none
Frequently Asked Questions
Are exhaust noise legal in Colorado?
What are the exact exhaust noise limits in Colorado?
Street-legal exhaust noise picks
Gear that helps you mod without a ticket in Colorado.
Measure your exhaust at the test RPM before a fix-it ticket does.
Shop on AmazonA removable insert that brings a loud exhaust back under your state's limit.
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