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Colorado Exhaust & Muffler Laws (2026)

Info: Your vehicle needs an adequate muffler. A cutoff or bypass (which routes exhaust around the muffler) is prohibited, and so is any exhaust change that raises noise above the stock level.

InfoVerified Jul 22, 2026

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Your vehicle needs an adequate muffler. A cutoff or bypass (which routes exhaust around the muffler) is prohibited, and so is any exhaust change that raises noise above the stock level. Colorado sets no fixed decibel limit for passenger cars (C.R.S. § 42-4-225).

Official source: leg.colorado.gov →

General legal information, not legal advice — verify important decisions with a licensed attorney.

Exhaust & Muffler in states bordering Colorado

The same rule in each neighboring state LawLert has verified, from that state’s own official source.

ArizonaInfo
Your vehicle needs a working muffler. A muffler cutout or bypass (which routes exhaust around the muffler) is prohibited, and excessive fumes or smoke are barred. A violation carries a civil penalty. Arizona sets no fixed decibel limit (A.R.S. § 28-955).
Verified Jul 23, 2026 · Source: azleg.gov · Full Arizona rule →
KansasInfo
Your vehicle needs a muffler or other effective noise-suppressing system in good order, and cutouts and bypasses (which route exhaust around the muffler) are prohibited, while excessive noise is barred. Kansas sets no fixed decibel limit (K.S.A. § 8-1739).
Verified Jun 19, 2026 · Source: kslegislature.gov · Full Kansas rule →
NebraskaInfo
Your vehicle needs a muffler or other noise-suppressing system in good working order, cutouts and bypasses (which route exhaust around the muffler) are unlawful, and changes that increase noise are banned. Nebraska sets no fixed decibel limit (Neb. Rev. Stat. § 60-6,286).
Verified Jun 19, 2026 · Source: nebraskalegislature.gov · Full Nebraska rule →
New MexicoInfo
Your vehicle needs a muffler in good working order, and a cutout or bypass (which routes exhaust around the muffler) is prohibited while excessive or unusual noise is barred. New Mexico sets no fixed decibel limit (N.M. Stat. § 66-3-844).
Verified Jul 30, 2026 · Source: nmonesource.com · Full New Mexico rule →
OklahomaInfo
Your vehicle needs a muffler or other noise-suppressing system, a cutout or bypass (which routes exhaust around the muffler) is prohibited, and so is any exhaust change that's louder than the factory (OEM) setup. Oklahoma sets no fixed decibel limit (47 O.S. § 12-402).
Verified Jun 19, 2026 · Source: oscn.net · Full Oklahoma rule →
UtahInfo
Your vehicle needs a muffler or other effective noise-suppressing system in good working order, and a cut-out, bypass or similar device (which routes exhaust around the muffler) is prohibited. Utah sets no fixed decibel limit (Utah Code § 41-6a-1626).
Verified Jun 19, 2026 · Source: le.utah.gov · Full Utah rule →
WyomingInfo
Your vehicle needs a muffler or other effective noise-suppressing system in good working order, and a cut-out, bypass or similar device (which routes exhaust around the muffler) is prohibited. Wyoming sets no fixed decibel limit (Wyo. Stat. § 31-5-953).
Verified Jul 22, 2026 · Source: wyoleg.gov · Full Wyoming rule →

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