Air Switching Valve

Not used on Omni and Horizon, the purpose of this valve is to switch the injection air from the exhaust ports to a point downstream after engine warmup. This prevents the air injection system from interfering with the operation of the Exhaust Gas Recirculation System.

A vacuum signal from either a coolant control engine vacuum switch (CCEVS) or vacuum solenoid causes the switching valve to open, allowing air pump air to flow to the exhaust ports. When CCEVS shuts off vacuum signal to switching valve, a bleed orifice in vacuum line of combination valve allows vacuum to go to zero, causing valve to switch air pump air to injection point downstream.

Downstream location is in the exhaust pipe just behind mini-catalyst on 6 cyl. engines and at base of right exhaust manifold above power heat control valve on most V8 engines. On California 318" V8 engines, injection point is in the main catalyst between the reduction and oxidation catalyst.