For 1990-2009 cars

### Cleaning Procedure

1. Remove the fuel rail with injectors. Refer to Fuel Rail and Injectors Removal.
2. Remove the evaporative emission hoses/pipes. Refer to Evaporative Emission Hoses/Pipes Replacement - Engine.
3. Remove the evaporative emission (EVAP) canister vent solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
4. Remove the throttle body and gasket. Refer to Throttle Body Removal.
5. Clean the intake manifold in solvent.

Caution: Refer to Safety Glasses Caution in the Preface section.

6. Dry the intake manifold with compressed air.

### Inspection Procedure

1. Inspect the manifold for the following conditions:

• | Loose threaded inserts or studs.

• | Damaged gasket or sealing surfaces.

• | Damaged or broken vacuum fittings.

• | Debris or restrictions within the passages of the manifold.

• | Inspect the composite intake manifold assembly for cracks or other damage.

2. Inspect the intake manifold cylinder head deck for warpage.

2.1. | Locate a straight edge across the intake manifold cylinder head deck surface.

Position the straight edge across a minimum of two runner port openings.

2.2. | Insert a feeler gage between the intake manifold and the straight edge.

An intake manifold with warpage in excess of 3 mm (0.118 in) over a 200 mm (7.87 in) area is warped and should be replaced.