For 1990-2009 cars only
- Remove the positive crankcase ventilation (PCV) valve. Refer to Positive Crankcase Ventilation Valve Replacement .
- Blow air into the cylinder head side of the PCV valve.
- Check that air passes through the PCV valve easily.
- Blow air into the intake manifold side of the PCV valve.
- Check that air passes through the PCV valve with high resistances.
- If the PCV valve fails either test, replace the PCV valve. Refer to Positive Crankcase Ventilation Valve Replacement .
- Inspect the PCV hose for damage, restrictions, or leaks. Replace the hose as necessary.
- Inspect all PCV system passages and connections for leaks or restrictions. Repair as necessary.
Caution: Refer to Fuel Vapors in Evaporative Emission Components Caution in the Preface section.
