Washington driving lawsExhaust & Muffler

Washington Exhaust & Muffler Laws (2026)

Info: Your vehicle needs a muffler in good working order.

InfoVerified Jun 19, 2026

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).

Official source: app.leg.wa.gov

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