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Arizona Exhaust & Muffler Laws (2026)

Info: 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.

InfoVerified Jul 23, 2026

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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).

Official source: azleg.gov →

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

Exhaust & Muffler in states bordering Arizona

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

CaliforniaInfo
Your vehicle needs an adequate muffler, you can't run a cutout or bypass (which routes exhaust around the muffler), vehicles under 6,000 pounds are capped at 95 decibels measured by the SAE J1169 test, and any aftermarket exhaust has to be legal under California Air Resources Board (CARB) rules (Cal. Veh. Code §§ 27150-27151, 27156).
Verified Jun 19, 2026 · Source: leginfo.legislature.ca.gov · Full California rule →
ColoradoInfo
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).
Verified Jul 22, 2026 · Source: leg.colorado.gov · Full Colorado rule →
NevadaInfo
Your vehicle needs a muffler in good working order that meets the Department's rules, and cutouts and bypasses (which route exhaust around the muffler) are banned on the highway. No fixed decibel limit is confirmed (NRS § 484D.415).
Verified Jun 19, 2026 · Source: leg.state.nv.us · Full Nevada 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 →
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 →

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