Aftermarket Exhaust in Connecticut
Replacing the exhaust system is legal in Connecticut, but a muffler in good working order is required and cutouts or bypasses are prohibited. Modifications that make the exhaust louder than the originally installed muffler are prohibited.
Verified against primary sources · August 2026
What the law says
Replacing the exhaust system is legal in Connecticut, but a muffler in good working order is required and cutouts or bypasses are prohibited. Modifications that make the exhaust louder than the originally installed muffler are prohibited. Removing the catalytic converter is prohibited by federal law (Clean Air Act § 203) regardless of state rules. Gutted mufflers and noise amplification are specifically banned. Connecticut requires a statewide biennial emissions test.
Specific Limits
- Cutouts
- prohibited
- Muffler required
- Yes
- Catalytic converter
- removal prohibited by federal law
Exceptions & Exemptions
Exhaust system must not exceed noise limits, muffler must be in good working order and cannot be modified to amplify or increase noise, catalytic converter removal prohibited on emissions-controlled vehicles, cutouts and bypasses not permitted
Frequently Asked Questions
Are aftermarket exhaust legal in Connecticut?
What are the exact aftermarket exhaust limits in Connecticut?
Are there exceptions for aftermarket exhaust in Connecticut?
Street-legal aftermarket exhaust picks
Gear that helps you mod without a ticket in Connecticut.
Cat-back systems keep your emissions equipment intact — the compliance-friendly route.
Shop on AmazonMeasure your exhaust at the test RPM before a fix-it ticket does.
Shop on AmazonAs an Amazon Associate, Is My Mod Legal earns from qualifying purchases made through these links, at no extra cost to you. We only recommend gear that helps you stay street-legal.