Aftermarket Exhaust in Oklahoma
Replacing the exhaust system is legal in Oklahoma, 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 specifically prohibited.
Verified against primary sources · August 2026
What the law says
Replacing the exhaust system is legal in Oklahoma, 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 specifically prohibited. Removing the catalytic converter is prohibited by federal law (Clean Air Act § 203) regardless of state rules. Oklahoma has no state inspection program.
Specific Limits
- Cutouts
- prohibited
- Muffler required
- Yes
- Louder than stock
- prohibited by statute
- Catalytic converter
- removal prohibited by federal law
Exceptions & Exemptions
Aftermarket exhaust systems must include a muffler in good working order and cannot exceed noise limits. Catalytic converters required on vehicles originally equipped with them. Cutouts, bypasses, or similar devices that allow exhaust to exit without passing through the muffler are prohibited.
Frequently Asked Questions
Are aftermarket exhaust legal in Oklahoma?
What are the exact aftermarket exhaust limits in Oklahoma?
Are there exceptions for aftermarket exhaust in Oklahoma?
Street-legal aftermarket exhaust picks
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