No, Washington prohibits exhaust systems producing excessive noise under RCW 46.37.380, with local jurisdictions like Seattle and Spokane enforcing stricter decibel limits. Modified exhausts exceeding 95 dB (measured 50 feet away) violate state law, and cities may impose additional fines or impoundment. Compliance with 2026 EPA standards is now audited more aggressively by the Washington State Patrol.
Key Regulations for Loud Exhausts in Washington
- State Decibel Limit: RCW 46.37.380 caps exhaust noise at 95 dB when measured 50 feet from the vehicle, exceeding federal EPA standards by 5 dB. Violations trigger citations under WSP enforcement protocols.
- Local Ordinances: Cities like Seattle (SMC 11.75.030) and Spokane (SMC 10.16.030) mandate compliance with stricter noise ordinances, often requiring mufflers in good working order and prohibiting “cutouts” or bypass pipes.
- Modification Restrictions: Aftermarket exhaust systems must maintain original equipment noise levels; alterations requiring DOT or EPA certification (e.g., 40 CFR Part 205) are scrutinized during annual inspections.
Enforcement Notes: The Washington State Patrol’s 2026 compliance initiative targets vehicles with modified exhausts during routine traffic stops, with penalties escalating for repeat offenses. Impoundment is authorized for vehicles exceeding 100 dB under local ordinances.