Senate Transportation considers requiring federal compliance stamp on mufflers

The Senate Transportation Committee turned to page 32, section 29 of the House draft to discuss exhaust and muffler requirements for vehicles. Members proposed inserting language that exhaust systems meet federal deceleration/noise standards and discussed using the federal compliance stamp on mufflers (cited as meeting 49 USC requirements) as an inspection proxy.

Several members and stakeholders raised practical inspection concerns: some mufflers are enclosed in cladding or are internal and cannot be visually inspected without disassembly, which would be impractical at an inspection station. Wils Harley‑Davidson (referenced in committee discussion) was cited as advising inspectors might not be able to see the stamp on some motorcycle mufflers because of cladding or mounting style.

Committee members proposed a compromise: keep the federal‑stamp requirement as evidence of compliance but add a proviso allowing an inspector to assume the stamp is present and proceed with a visual integrity check if the stamp cannot reasonably be observed because of cladding or muffler position. A committee member explained, "Having the stamp is compliance with law," and lawmakers discussed language that would specifically cite 49 USC in the Senate draft.

The committee asked staff to draft the amendment language that ties the muffler standard to federal compliance (49 USC) and to add a provision clarifying inspection practice when the stamp is not visible. Members agreed to circulate the amendment language and move the measure to the conference committee.