Air Injection: Description and Operation

Air Injection System:

PURPOSE

The air injection system adds a controlled amount of air to the exhaust gases aiding oxidation of hydrocarbons and carbon monoxide in exhaust stream. The system does not interfere with the ability of the EGR system to control nitrous oxide (NOx) emissions.


CONSTRUCTION

The air injection system consists of:

^ Two belt-driven air pumps

^ Two relief valves

^ Rubber hoses and check valves

The check valves protect the hoses and injection tubes from hot exhaust gases.


OPERATION

Air passes through the filter fans at the front of the air pumps, where foreign matter is filtered out by centrifugal force. This filtered air is injected into the exhaust, ahead of the catalytic converter, where it assists in the oxidation process, but does not interfere with exhaust gas recirculation. There is no air switching valve, diverter valve, or air switching valve solenoid in this system.