Inspection Procedure

Inspect the throttle body studs and threaded inserts for looseness or damaged threads.

Fig 1: View Of Throttle Body & Nuts
Courtesy of GENERAL MOTORS CORP.
Inspect the wire harness stud and threaded insert for looseness or damaged threads.
Inspect the fuel rail bolt inserts for looseness or damaged threads.

Fig 2: View Of Fuel Rail W/Injectors
Courtesy of GENERAL MOTORS CORP.
Inspect the intake manifold vacuum passages for debris or restrictions.
Inspect for damaged or broken vacuum fittings, damaged MAP sensor (714) mounting bore, or broken MAP sensor retaining tabs.

Fig 3: View Of MAP Sensor
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Inspect the composite intake manifold assembly for cracks or other damage.
Inspect the areas between the intake runners.
Inspect all the gasket sealing surfaces for damage.
Inspect the fuel injector bores for excessive scoring or damage.

Fig 4: Inspecting Intake Manifold Cylinder Head Deck For Warpage
Courtesy of GENERAL MOTORS CORP.
Inspect the intake manifold cylinder head deck for warpage.
1. Locate a straight edge across the intake manifold cylinder head deck surface.
  Position the straight edge across a minimum of 2 runner port openings.
2. Insert a feeler gage between the intake manifold and the straight edge.
  A 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.
Install the MAP sensor (714).

Fig 5: View Of MAP Sensor
Courtesy of GENERAL MOTORS CORP.

NOTE: Refer to Fastener Notice .

Install the EVAP canister purge solenoid valve, bolt, and isolator.
Tighten: Tighten the EVAP valve bolt to 10 N.m (89 lb in).