For 1990-2009 cars

1. Clean the intake manifold mating surfaces.
2. Inspect the intake manifold (1) for damage.
3. Inspect the intake manifold for cracks near metallic inserts.

Warning: Refer to Safety Glasses and Compressed Air Warning in the Preface section.

4. Clean the passages (1) with compressed air (2) if necessary. Use a maximum of 172 kPa (25 psi) of air pressure.
5. Replace the intake manifold as necessary.