AIR37 - Inspect For Valve Function

NOTE: Check valve will "burble" as air is drawn in.

^ Key ON, engine RUNNING.

^ Listen for escaping exhaust gas or feel for escaping gas (only if engine temperature is at an acceptable level).

^ Is any exhaust gas escaping?

YES -- Replace PAIR valve. Verify drive concern.

NO -- For 49 state vehicles, go to AIR2. AIR2 - Check For Obstructions

For California vehicles, go to AIR38. AIR38 - Check Pair Valve Operation For Open