PENNSYLVANIA

Motorcycle Laws

(a) Condition of Exhaust System - All components of the exhaust system shall be in safe
operating condition as described in §175.160 (relating to inspection procedure) .

(b) Exhaust System Requirements - 

A motorcycle shall be equipped with a muffler or other effective noise-suppressing system in good
working order and in constant operation. A muffler or exhaust system may not be
equipped with a cutout, bypass or similar device and a muffler may not show evidence
of external repair. 

Notice the wording is always the same and left purposefully vague  by 
leaving out "Factory Installed or Equivalent".

These drafting of these laws are clearly being left vague and unenforceable
probably under pressure from the various campaign contributing motorcycle 
groups and lobbyists.

(1) The exhaust system of a motorcycle may not be modified in a manner which will
     amplify or increase noise emitted by the motor of the vehicle above the maximum
     level permitted by Chapter 157 (relating to established sound levels).

(2) An exposed exhaust systems shall be equipped with adequate heat shield or
     protective system or be located to prevent contact by operator or passenger.

Inspection Stations Definitions

Motorcycle - A motor vehicle having a seat or saddle for the use of the rider 
and designed to travel on not more than 3 wheels in contact with the ground.

Motorcycle Inspection Station - An inspection station appointed to inspect only motorcycles

The Question is why are the illegal motorcycles passing the inspection with exhausts 
that do not meet EPA standards.  Unless they are reinstalling the factory exhaust back
on before the inspection!