Impreza Wagon FWD F4-1820cc 1.8L SOHC (1995)
Air Injection Muffler: Testing and Inspection
Air Suction Valve
1.
Start the engine.
2.
Disconnect the vacuum hose to the air suction valve (ASV) and apply vacuum (to activate PAIR system).
3.
Disconnect the hose between the silencer and the air cleaner. Note the volume of noise.
4.
Disconnect the hose between the ASV and the silencer. The sound should be much louder. Replace the silencer if the difference in noise levels was
minimal.
5.
Inspect the silencer for damage or melting. If the silencer shows signs of melting, it is probable the ASV is bad.