Aftermarket Exhaust in Maine
Replacing the exhaust system is legal in Maine, but a muffler in good working order is required and cutouts or bypasses are prohibited. There is no statutory 'no louder than stock' rule — the standard is that the exhaust must not produce excessive or unusual noise.
Verified against primary sources · August 2026
What the law says
Replacing the exhaust system is legal in Maine, but a muffler in good working order is required and cutouts or bypasses are prohibited. There is no statutory 'no louder than stock' rule — the standard is that the exhaust must not produce excessive or unusual noise. Removing the catalytic converter is prohibited by federal law (Clean Air Act § 203) regardless of state rules. Maine treats a non-motorcycle exhaust at or below 95 dB (SAE J1169) as compliant. Annual safety inspection applies.
Specific Limits
- Cutouts
- prohibited
- Muffler required
- Yes
- Louder than stock
- not addressed; excessive noise standard applies
- Catalytic converter
- removal prohibited by federal law
Exceptions & Exemptions
Exhaust system must not exceed noise levels that would be unreasonable or disturbing. Muffler must be in good working order and cannot be modified to amplify noise. Catalytic converters required on vehicles originally equipped with them.
Frequently Asked Questions
Are aftermarket exhaust legal in Maine?
What are the exact aftermarket exhaust limits in Maine?
Are there exceptions for aftermarket exhaust in Maine?
Street-legal aftermarket exhaust picks
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