GM Service Manual Online
For 1990-2009 cars only

Important: 

   • 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.
   • For vehicles equipped with the PUP catalytic converter, do not splash any solvent into the converter element.

  1. Clean the exhaust manifold with solvent.
  2. Caution: Refer to Safety Glasses Caution in the Preface section.

  3. Dry the exhaust manifold with compressed air.
  4. Inspect for a loose or damaged heat shield.
  5. Clean the exhaust manifold mating surface.
  6. Measure the exhaust manifold mounting face for warpage using a straight edge and a feeler gage.
  7. Exhaust Manifold Maximum Warpage
    0.10 mm (0.004 in)

  8. If the warpage is greater than the maximum, replace the exhaust manifold.