Exhaust Manifold Replacement - Right Side 4.8L, 5.3L, 6.0L,and 6.2L

1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1.
2. Fully raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle.
3. Remove the catalytic converter to exhaust manifold nuts, 1500 series shown, 2500 series similar.



4. Remove the right wheelhouse liner. Refer to Front Wheelhouse Liner Replacement - Right Side.
5. Remove the spark plug wires (1) from the spark plugs.

5.1.	Twist the spark plug wire boot a 1/2 turn.

5.2.	Pull only on the boot in order to remove the wire from the spark plug.

6. Remove the spark plug wires from the ignition coils.

6.1.	Twist the spark plug wire boot a 1/2 turn.

6.2.	Pull only on the boot in order to remove the wire from the ignition coil.




7. Remove the oil level indicator tube bolt (419).
8. Remove the oil level indicator tube (420) from the engine block.



9. Remove the exhaust manifold bolts and exhaust manifold.
10. Remove and discard the exhaust manifold gasket.
11. Remove and discard the exhaust manifold seal.



12. If replacing the exhaust manifold, remove the exhaust manifold heat shield bolts, and shield from the exhaust manifold.

Note: 

Caution: Refer to Fastener Caution in the Preface section.




1. If the exhaust manifold was replaced, position and install the exhaust manifold heat shield, and bolts to the exhaust manifold.

Tighten
Tighten the bolts to 9 N·m (80 lb in).




2. Clean the threads of the exhaust manifold bolts.
3. Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 10953488), or equivalent to the threads of the exhaust manifold bolts.
4. Install a NEW catalytic converter seal to the exhaust manifold.
5. Position the NEW exhaust manifold gasket and exhaust manifold to the cylinder head.
6. Ensure that the catalytic converter seal is seated to the catalytic converter.
7. Install the exhaust manifold bolts.

Tighten

1. Tighten the bolts a first pass to 15 N·m (11 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work toward the outside bolts.
2. Tighten the bolts a final pass to 20 N·m (15 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work toward the outside bolts.
8. Using a flat punch, bend the gasket tab at the rear of the gasket around the cylinder head edge.




Note: The O-ring seal may be reused if not cut or damaged.

9. Inspect the O-ring seal (421) for cuts or damage, replace as necessary.
10. Lubricate the O-ring seal (421) with clean engine oil.
11. Install the oil level indicator tube (420) to the engine block.
12. Install the oil level indicator tube bolt (419).

Tighten
Tighten the bolt 25 N·m (18 lb ft).




13. Install the spark plug wires (1) to the spark plugs.
14. Install the spark plug wires to the ignition coils.
15. Inspect the spark plug wires for proper installation.

15.1.

Push sideways on each boot in order to inspect the seating.

15.2.

Reinstall any loose boot.

16. Install the right wheelhouse liner. Refer to Front Wheelhouse Liner Replacement - Right Side.
17. Fully raise and support the vehicle.



18. Install the catalytic converter to exhaust manifold nuts, 1500 series shown, 2500 series similar.

Tighten
Tighten the nuts to 50 N·m (37 lb ft).

19. Partially lower the vehicle in order to work through the wheel opening.

Install the HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1.

Exhaust Manifold Replacement - Right Side 6.6L

1. Remove the wheelhouse liner. Refer to Front Wheelhouse Liner Replacement - Right Side.



2. Perform the following steps working through the wheelhouse opening, remove the exhaust pipe to turbocharger exhaust pipe bracket bolt.



3. Remove the exhaust pipe to exhaust manifold bolts (1) and bracket.



4. Remove the exhaust manifold heat shield bolts (1) and shield.



5. Remove the exhaust manifold bolts and nuts in the proper sequence.



6. Remove the exhaust manifold and exhaust manifold to pipe gasket.



7. Remove the oil level indicator tube bolt (2) and rotate the oil level indicator tube out of the way.
8. Remove and discard the exhaust manifold gasket (1).

1. Install a NEW exhaust manifold gasket (1) onto the studs.

Caution: Refer to Fastener Caution in the Preface section.

2. Rotate the oil level indicator tube into position and install the oil level indicator tube bolt (2) and tighten to 21 N·m (15 lb ft).



3. Position a NEW exhaust pipe gasket between the exhaust manifold and exhaust pipe. Align the tabs on the gasket to face downward.
4. Install the exhaust manifold onto the studs.



5. Install and tighten the exhaust manifold bolts and nuts in the sequence shown and tighten to 57 N·m (42 lb ft).
6. Tighten the 4 center bolts/nuts an additional pass to 57 N·m (42 lb ft).



7. Position the exhaust manifold heat shield to the manifold and install the exhaust manifold bolts (1) and tighten to 10 N·m (89 lb in).



8. Install the exhaust pipe bracket and the exhaust pipe to exhaust manifold bolts (1).



9. Tighten the exhaust pipe to exhaust manifold bolts in the sequence shown (4, 5, and 6) to 53 N·m (39 lb ft).



10. Install the exhaust pipe to turbocharger exhaust pipe bracket bolt and tighten to 34 N·m (25 lb ft).
11. Install the wheelhouse liner. Refer to Front Wheelhouse Liner Replacement - Right Side.
12. Lower the vehicle.

Exhaust Manifold Replacement - Right Side 4.3L

1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1.
2. Remove the catalytic converter to exhaust manifold nuts (1).
3. Lower the vehicle.



4. Remove the exhaust manifold heat shield bolts and shield.
5. Remove the spark plugs. Refer to Spark Plug Replacement.
6. Reposition the spark plug wires out of the way, if necessary.



7. Remove the exhaust manifold bolts.
8. Remove the exhaust manifold and gaskets (1). Discard the gaskets.
9. Remove the exhaust manifold to catalytic converter seal (2). Discard the seal.

1. Install a NEW exhaust manifold to catalytic converter seal (2) into the exhaust manifold.
2. Place the exhaust manifold into position and install the manifold studs to the catalytic converter.
3. Place the NEW exhaust manifold gaskets (1) between the manifold and the cylinder head.

Caution: Refer to Fastener Caution in the Preface section.

4. Install the exhaust manifold bolts and stud.

Tighten
Tighten the bolts/stud to 30 N·m (22 lb ft).




5. Install the spark plugs. Refer to Spark Plug Replacement.
6. Position the exhaust manifold heat shield to the manifold and install the bolts.

Tighten
Tighten the bolts to 9 N·m (80 lb in).




7. Raise and support the vehicle.
8. Install the catalytic converter to exhaust manifold nuts (1).

Tighten
Tighten the nuts to 50 N·m (37 lb ft).

9. Lower the vehicle.