4523 - Exhaust systems, mufflers and noise control.

     § 4523.  Exhaust systems, mufflers and noise control.        (a)  Compliance with established sound levels.--Every motor     vehicle operated on a highway shall be constructed, equipped,     maintained and operated so as not to exceed the sound level for     the vehicle as prescribed in regulations promulgated by the     department. The test procedures and instrumentation to be     utilized shall also be established by regulation.        (b)  Compliance with exhaust requirements.--In addition to     any requirements established under sections 4531 (relating to     emission control systems) and 4532 (relating to smoke control     for diesel-powered motor vehicles), every motor vehicle shall be     constructed, equipped, maintained and operated so as to prevent     engine exhaust gases from penetrating and collecting in any part     of the vehicle occupied by the driver or passengers.        (c)  Mufflers and related equipment.--Every motor vehicle     shall be equipped with a muffler or other effective noise     suppressing system in good working order and in constant     operation and no muffler or exhaust system shall be equipped     with a cutout, bypass or similar device.        (d)  Unauthorized modification of equipment.--No person shall     modify the exhaust system of a motor vehicle in a manner which     will amplify or increase the noise emitted by the motor of the     vehicle above the maximum levels permitted under subsection (a)     or violate the provisions of subsection (b). Headers and side     exhausts are permitted provided the vehicle meets all the     requirements of this section.        (e)  Fire equipment and racing vehicles.--This section does     not apply to fire equipment or to racing vehicles being operated     in an organized racing or competitive event conducted under a     permit issued by local authorities.