← Oregon driving laws›Exhaust & Muffler

Oregon Exhaust & Muffler Laws (2026)

Info: Your vehicle needs a proper exhaust. On the Department of Environmental Quality's stationary test, passenger cars built in 1976 or later are capped at 88 decibels, and cars built before 1976 at 92 decibels, measured at 25 feet (Or. Rev. Stat. § 815.250).

InfoVerified Jun 19, 2026

Vehicle rules change at the state line — and in your state.Track them in the free LawLert iPhone app: it alerts you when you cross into a state where they differ, and when they change in your state. No account.Get the app

Official source: oregonlegislature.gov →

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

Exhaust & Muffler in states bordering Oregon

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 →
IdahoInfo
Your vehicle needs a muffler in good order, and cutouts and bypasses (which route exhaust around the muffler) are banned, along with changes that make the exhaust louder — in Idaho, "excessive noise" means more than 92 decibels measured at 20 feet (Idaho Code §§ 49-937, 49-106).
Verified Jun 19, 2026 · Source: legislature.idaho.gov · Full Idaho 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 →
WashingtonInfo
Your vehicle needs a muffler in good working order, cutouts and bypasses (which route exhaust around the muffler) are prohibited, and so is exhaust amplified beyond the factory muffler. Washington sets no decibel limit in statute (RCW § 46.37.390).
Verified Jun 19, 2026 · Source: app.leg.wa.gov · Full Washington rule →

Don't get caught off guardCross into a state where this law is different and the free iPhone app tells you what changed, even with the app closed. It also alerts you when a law you track changes where you live. No account.Get the free app

Track this law — get alerted when it changes

We watch the official sources behind Oregon vehicle rules. If a tracked rule changes, you get one short email — never more than one a week. Free, unsubscribe anytime.