Aftermarket Exhaust in Maryland
Replacing the exhaust system is legal in Maryland, but a muffler in good working order is required and cutouts or bypasses are prohibited.
Verified against primary sources · August 2026
What the law says
Replacing the exhaust system is legal in Maryland, but a muffler in good working order is required and cutouts or bypasses are prohibited. Removing the catalytic converter is prohibited by federal law (Clean Air Act § 203) regardless of state rules. Smoke limits apply separately, and Maryland's VEIP program requires emissions inspection.
Specific Limits
- Cutouts
- prohibited
- Muffler required
- Yes
- Catalytic converter
- removal prohibited by federal law
Exceptions & Exemptions
Must not exceed noise limits, muffler required, no straight pipes or cutouts allowed, catalytic converter must remain intact
Frequently Asked Questions
Are aftermarket exhaust legal in Maryland?
What are the exact aftermarket exhaust limits in Maryland?
Are there exceptions for aftermarket exhaust in Maryland?
Street-legal aftermarket exhaust picks
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