The air injection pump is designed to introduce clean air to the engine exhaust as it exits the exhaust manifold or exhaust headers. Exhaust gases are at their hottest as they leave the combustion chambers. Introducing oxygen to the exhaust at this point allows continued burning of the fuel mixture as it travels down the exhaust system and ultimately out the tailpipe. The air injection pump is responsible for supplying fresh pressurized oxygen to the exhaust stream through header or exhaust manifold and or before the catalytic converter. The components of this system are the air pump, the diverter valve, the air distribution manifold; both known as exhaust manifold and exhaust headers. Pump Only Air flow pipe to Exhaust Manifold may need to be replaced. Drive belt will not be included Primarily used on older automotive emissions control systems in the 70's and 80's, the Air Injection Pump is used to pump more air into the exhaust stream to aid in burning of harmful exhaust particles. Normally mounted on the front of the engine and driven by a belt, it will have a pipe running into the exhaust manifold.