Exhaust Noise in Missouri
Missouri 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
Missouri 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. Missouri's wording is unusually strong: the muffler must 'quiet the maximum possible exhaust noise,' and cutouts must be closed and disconnected.
Specific Limits
- Statewide decibel limit
- none
Frequently Asked Questions
Are exhaust noise legal in Missouri?
What are the exact exhaust noise limits in Missouri?
Street-legal exhaust noise picks
Gear that helps you mod without a ticket in Missouri.
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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