2010 Pennsylvania Code
Title 75 - VEHICLES
Chapter 77 - Snowmobiles and All-Terrain Vehicles
7743 - Mufflers and noise control.

     § 7743.  Mufflers and noise control.
        (a)  General rule.--It is unlawful to operate a snowmobile or
     an ATV which is not equipped at all times with a muffler in good
     working order which blends the exhaust noise into the overall
     snowmobile or ATV noise and is in constant operation to prevent
     excessive or unusual noise. The exhaust system shall not emit or
     produce a sharp popping or crackling sound. The sound intensity
     produced by a snowmobile shall not exceed 82dbA when measured in
     accordance with SAE Recommended Practice J 192 Exterior Sound
     Level for Snowmobiles, as amended. The department may by
     regulation adopt more stringent noise requirements for
     snowmobiles. The department shall by regulation adopt noise
     requirements for in-use operation of ATV's using measurement
     procedures in accordance with ANSI/SAE Recommended Practice J
     1287 March 1982, Measurement of Exhaust Level of Stationary
     Motorcycles. The sound level intensity produced by an ATV shall
     not exceed 99dbA, or decibels, when measured at 20 inches.
        (b)  Modified mufflers prohibited.--It is unlawful to modify
     a muffler or to operate a snowmobile or an ATV with a modified
     muffler so as to increase the sound level of the snowmobile or
     ATV above the level allowed by this section.
        (c)  Exception.--This section does not apply to organized
     races or similar competitive events.
     (July 11, 1985, P.L.220, No.56, eff. 60 days)