Inspection Procedure

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the throttle body studs and threaded inserts for looseness or damaged threads.
Inspect the wire harness stud and threaded insert for looseness or damaged threads.

Fig 1: Throttle Body & Nut
Courtesy of GENERAL MOTORS CORP.
Inspect the fuel rail bolt inserts for looseness or damaged threads.
Inspect the intake manifold vacuum passages for debris or restrictions.

Fig 2: Fuel Rail & Injectors
Courtesy of GENERAL MOTORS CORP.
Inspect for damaged or broken vacuum fittings, damaged MAP sensor (1) mounting bore, or broken MAP sensor retaining tabs.
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.

Fig 3: MAP Sensor
Courtesy of GENERAL MOTORS CORP.
Inspect the fuel injector bores for excessive scoring or damage.
Inspect the intake manifold cylinder head deck for warpage.
1. 9.1. Locate a straight edge across the intake manifold cylinder head deck surface.
  Position the straight edge across a minimum of two runner port openings.
2. 9.2. 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.
Fig 4: Inspecting Intake Manifold Cylinder Head Deck For Warpage
Courtesy of GENERAL MOTORS CORP.
Install the MAP sensor (1).
NOTE: Refer to FASTENER NOTICE in Cautions and Notices.
Install the EVAP solenoid, bolt, and isolator.
Tighten

Tighten the EVAP solenoid bolt to 10 N.m (89 lb in).

Fig 5: MAP Sensor
Courtesy of GENERAL MOTORS CORP.