Aftermarket Exhaust in Delaware
Replacing the exhaust system is legal in Delaware, 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 Delaware, 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. The muffler must meet the manufacturer's specifications, and selling gutted mufflers or straight exhausts is banned. Emissions are checked at registration inspection.
Specific Limits
- Cutouts
- prohibited
- Muffler required
- Yes
- Catalytic converter
- removal prohibited by federal law
Exceptions & Exemptions
Must not exceed noise limits, muffler required, catalytic converter must remain intact, no cutouts or bypasses allowed
Frequently Asked Questions
Are aftermarket exhaust legal in Delaware?
What are the exact aftermarket exhaust limits in Delaware?
Are there exceptions for aftermarket exhaust in Delaware?
Street-legal aftermarket exhaust picks
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