Exhaust Manifold Cleaning and Inspection

WARNING: This page is about a different car, the 2002 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

Clean the exhaust manifold mating surfaces.
Clean the exhaust manifold.
Inspect the exhaust manifold mating surfaces for damage.

Fig 1: Exhaust Manifold
Courtesy of GENERAL MOTORS CORP.
Inspect the exhaust manifold flange for straightness, using a straight edge and a feeler gauge.
If the exhaust manifold flange is warped more than 0.05 mm (0.002 in) replace the exhaust manifold.

Fig 2: Inspect The Exhaust Manifold Flange For Straightness, Using A Straight Edge And A Feeler Gauge
Courtesy of GENERAL MOTORS CORP.