Pump Type - The spinning vanes of the air pump force air into the diverter valve. During acceleration air is forced through the diverter valve, the check valve, the air injection manifold, and into the exhaust stream. During deceleration the diverter valve blocks air flow, preventing a backfire that could damage the exhaust system. When needed, the diverter valve will release excess pressure to the air cleaner.
Pulse Type - As exhaust gases travel down the exhaust passages, the vacuum created draw fresh oxygen into the air injection system. Fresh air then travels through the diverter valve, check valve and to the exhaust manifold.
For the Smog Test: During the visual inspection portion of the smog test the smog technician will be inspecting your vehicle's air injection system. If your vehicle is equipped with a pump air injection system the technician will be checking for the proper connection of the injection system plumbing, all hoses, lines, valves and smog pump.
The smog technician will also examine the air pump belt for proper tension and damage. During your at-home check up ensure all connections are intact and components present. If it appears there are missing parts or open ends seek repair assistance from a certified smog repair station before subjecting your vehicle to the smog inspection.
For vehicles equipped with the pulse air injection system, the technician will only inspect the injection pipes and valves.
Note: During the smog test the air injection system is only visual inspected. The smog technician will not insure the proper operation of this system, rather he or she will only verify that the system is installed and properly connected.