Concerns installation, modification, and sale of certain mufflers and exhaust systems; requires inspection of mufflers and exhaust systems.

S 507 (New Jersey) requires all motor vehicles to have mufflers and exhaust systems that do not amplify noise beyond the original factory level, prohibiting modifications that increase sound. It directly affects vehicle owners, auto body repair shops, and inspectors by mandating that exhaust systems be inspected for excessive noise during annual vehicle safety/emissions checks. The bill amends existing laws to specify that repairs or installations must not exceed original noise levels, with violations punishable by fines up to $500. Collector vehicles (e.g., historic or low-mileage cars) may be exempt from certain inspection requirements under defined criteria. This focuses on reducing noise pollution through enforceable inspection standards rather than restricting vehicle types.