Removal Procedure
Important: The intake manifold, throttle body, fuel rail, and injectors may be
 removed as an assembly. If not servicing the individual components, remove
   the manifold as a complete assembly.
- Remove the throttle body. Refer to 
Throttle Body Assembly Replacement 
  in Engine Controls - 4.8L, 5.3L,
 and 6.0L.
 
- Remove the fuel injectors. Refer to 
Fuel Injector Replacement 
  in Engine Controls - 4.8L, 5.3L,
 and 6.0L.
 
- Disconnect the following
 electrical connectors:
 
| •  | Manifold absolute pressure (MAP) sensor (1) | 
 
| •  | Exhaust gas recirculation (EGR) valve, if equipped. | 
 
- Remove the knock sensor harness electrical connector from the
 intake manifold.
 
- Set the electrical harness aside.
 
- If equipped, remove the
 following EGR pipe bolts:
 
- If equipped, remove the EGR pipe with valve.
 
- If equipped, remove the EGR pipe gasket from the exhaust manifold.
 
- If equipped with vacuum
assisted brakes, remove the vacuum brake booster hose from the rear  of the
  intake manifold.
 
- Remove the positive crankcase
 ventilation (PCV) hose with valve.
 
- Remove the MAP sensor
 (1) from the intake manifold.
 
- Remove the accelerator control cable bracket bolts (1).
 
- Remove the accelerator control cable bracket (2) from the intake
 manifold.
 
- Remove the evaporative
 emission (EVAP) purge solenoid vent tube by performing the following:
 
| 14.1.  | Remove the EVAP tube end (2) from the solenoid (1). | 
 
| 14.2.  | Squeeze the EVAP pipe quick connect fitting (3) retainer together. | 
 
| 14.3.  | Remove the EVAP tube end (3) from the vapor pipe. | 
 
- Remove the EVAP purge
 solenoid bolt (2), solenoid (3), and isolator (1) from the intake manifold.
 
- Remove the intake manifold
 bolts.
 
- Remove the intake manifold.
 
- Remove the intake manifold gaskets (1) from the intake manifold.
 
- Discard the old intake manifold gaskets.
 
- Clean and inspect the intake manifold. Refer to 
Intake Manifold Cleaning and Inspection 
  in the Engine Mechanical
 - 4.8L, 5.3L, and 6.0L Unit Repair.
 
- If equipped with EGR, clean the gasket surfaces of the EGR pipe
 and the exhaust manifold.
 
Installation Procedure
- Install new intake manifold gaskets (1) to the intake manifold.
 
- Install the intake manifold.
 
- Apply a 5 mm (0.20 in) band of threadlock GM U.S. P/N 12345382,
 Canada P/N 10953489, or equivalent to the threads  of the intake
manifold bolts.
 
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Install the intake
 manifold bolts.
 
Tighten
- Tighten the intake manifold bolts a first pass in sequence to
 5 N·m (44 lb in).
 
- Tighten the intake manifold bolts a final pass in sequence to
 10 N·m (89 lb in).
 
- Install the EVAP purge
 solenoid (3), isolator (1), and bolt (2) to the intake manifold.
 
Tighten
Tighten the EVAP purge solenoid bolt to 10 N·m (89 lb in).
- Install the EVAP purge
 solenoid vent tube to the solenoid (1) and vapor pipe.
 
- Install the accelerator control cable bracket (2) to the intake manifold.
 
- Install the accelerator control cable bracket bolts (1).
 
Tighten
Tighten the accelerator control cable bracket bolts to 10 N·m
 (89 lb in).
Important: Lightly coat the MAP sensor seal with clean engine oil before installing.
- Install the MAP sensor (1) to the intake manifold.
 
- Install the PCV hose with
 valve.
 
- If equipped with vacuum
assisted brakes, install the vacuum brake booster hose to the
rear  of the   intake manifold.
 
- If equipped, position
 a new EGR pipe gasket on the exhaust manifold.
 
- If equipped, install the EGR pipe with valve.
 
- If equipped, install the following EGR pipe bolts until snug:
 
- If equipped, tighten the EGR pipe bolts.
 
Tighten
|     •  | Tighten the EGR valve pipe-to-intake manifold bolts to 10 N·m
 (89 lb in). | 
 
|     •  | Tighten the EGR valve pipe-to-cylinder head bolts to 50 N·m
 (37 lb ft). | 
 
|     •  | Tighten the EGR valve pipe-to-exhaust manifold bolts to 30 N·m
 (22 lb ft). | 
 
- Route the electrical harness into position over the engine.
 
- Connect the knock sensor
 harness electrical connector to the intake manifold.
 
- Connect the following electrical connectors.
 
- Install the fuel injectors. Refer to 
Fuel Injector Replacement 
  in Engine Controls - 4.8L, 5.3L,
 and 6.0L.
 
- Install the throttle body. Refer to 
Throttle Body Assembly Replacement 
  in Engine Controls -
 4.8L, 5.3L, and 6.0L.