[box type="shadow"]Full exhaust systems are made of multiple components including the exhaust manifold, front pipe, catalytic converter, muffler and tailpipe.
Exhaust gases travel through piping of varying size before released into the air. Exhaust pipe specifications determine flow, gas velocity and back pressure.[/box]
[box type="shadow"]Location of Exhaust System and Discharge
No part of the exhaust system can be located where the fumes could cause burning, charring, damage to the fuel supply, the wiring or any combustible section of the vehicle. The system cannot discharge exhaust below the fuel tank or fuel tank filler pipe, forward of the semi’s cab or below the cab or sleeper compartment.
Installation Manner of the Exhaust System
The exhaust system must be securely fastened to the vehicle but may be installed on a hanger that allows for the movement of the system during the operation of the vehicle and that allows for the natural expansion and contraction of the exhaust fumes.
Prohibited Repair Techniques
The exhaust system cannot be repaired with temporary patches or wraps; permanent repair measures are required.
Upcoming Changes in Specifications
In October, 2010, the Environmental Protection Agency (EPA) and the DOT announced the first-ever rule designed to regulate emissions from the exhaust system of semis. The changes will take effect between 2014 and 2018. See the Resources section for a link the further information.[/box]