Exhaust Manifold Cleaning and Inspection

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Oxygen Sensor

Courtesy of GENERAL MOTORS CORP.

NOTE:

Do not reuse the exhaust manifold-to-cylinder head gaskets. Upon installation of the exhaust manifold, install a NEW gasket. An improperly installed gasket or leaking exhaust system may effect On-Board Diagnostics (OBD) II system performance.
Remove the oxygen sensor prior to cleaning the manifold. Do not submerge the oxygen sensor in cleaning solvent.

Remove the oxygen sensor from the manifold.
Clean the exhaust manifold in solvent.

WARNING: Refer to Safety Glasses Warning .

Dry the exhaust manifold with compressed air.
Inspect the heat shield for damage.

Fig 2: Checking Exhaust Manifold Mounting Face For Warpage

Courtesy of GENERAL MOTORS CORP.

Use a straight edge and a feeler gage and measure the exhaust manifold mounting face for warpage.
An exhaust manifold face with warpage in excess of 0.25 mm (0.0100 in) may cause an exhaust leak and may effect OBD II system performance. Exhaust manifolds not within specifications must be replaced.