Exhaust Pipe: Service and Repair

Exhaust Manifold Pipe Replacement

Removal Procedure

Caution: Refer to Hot Exhaust System Caution in Service Precautions.

Caution: Refer to Exhaust Parts Removal Caution in Service Precautions.





1. Raise and suitably support the vehicle. Refer to Vehicle Lifting.
2. Remove the engine shield bolts and shield, if necessary.





3. Remove the oil pan skid plate bolts and plate, if necessary.
4. If equipped with the 4.3L, 4.8L, 5.3L, 6.0L, or 8.1L engines, remove the exhaust muffler.





5. If equipped with a 6.0L or 8.1L engine, perform the following:
5.1. Remove the clip around the engine harness and the oxygen sensor pigtail.
5.2. Disconnect the Connector Position Assurance (CPA) retainer.
5.3. Disconnect the oxygen sensor electrical connector.
5.4. If replacing the exhaust manifold pipe, remove the oxygen sensor.





6. if equipped with a 6.0L or 8.1L engine, remove the exhaust manifold pipe nuts.





7. If equipped with the 6.6L engine, remove the exhaust muffler nuts.





8. If equipped with a 6.6L engine, loosen the exhaust pipe clamp.
9. Slide the exhaust pipe clamp up onto the exhaust pipe adapter.





10. If equipped with a 6.0L or 8.1L engine, remove the exhaust manifold pipe.
11. Slide the exhaust manifold pipe hanger out of the exhaust pipe hanger bracket.
12. Discard the exhaust manifold pipe seal.





13. If equipped with a 6.0L engine, with Regular Production Option (RPO) Y91, remove the exhaust manifold pipe.
14. Slide the exhaust manifold pipe hanger out of the exhaust pipe hanger bracket.
15. Discard the exhaust manifold pipe seal.





16. If equipped with a 6.6L engine, remove the exhaust manifold pipe.
17. Slide the exhaust manifold pipe hanger out of the exhaust pipe hanger bracket.

Installation Procedure

Notice: Refer to Exhaust System Clearance Notice in Service Precautions.





1. If equipped with a 6.6L engine, install the exhaust manifold pipe.
2. Apply water based lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
3. Slide the exhaust manifold pipe hanger into the exhaust pipe hanger bracket.





4. If equipped with a 6.0L engine, with RPO Y91, install a new exhaust manifold pipe seal to the exhaust manifold pipe.
5. Install the exhaust manifold pipe.
6. Apply lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
7. Slide the exhaust manifold pipe hanger into the exhaust pipe hanger bracket.





8. If equipped with a 6.0L or 8.1L engine, install a new exhaust manifold pipe seal to the exhaust manifold pipe.
9. Install the exhaust manifold pipe.
10. Apply lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
11. Slide the exhaust manifold pipe hanger into the exhaust pipe hanger bracket.





12. If equipped with the 6.6L engine, install the exhaust muffler nuts until snug.





Important: Ensure that the manifold pipe is square to the exhaust pipe adapter.

13. If equipped with a 6.6L engine, slide the exhaust pipe clamp down and around the pipe connection.

Notice: Refer to Fastener Notice in Service Precautions.

14. Tighten the exhaust pipe clamp and muffler nuts.
^ Tighten the exhaust pipe clamp to 40 Nm (30 ft. lbs.).
^ Tighten the exhaust muffler nuts to 40 Nm (30 ft. lbs.).





15. If equipped with a 6.0L or 8.1L engine, install the exhaust manifold pipe nuts.
^ Tighten the exhaust manifold pipe nuts to 50 Nm (39 ft. lbs.).





16. If equipped with a 6.0L or 8.1L engine, and the exhaust manifold pipe was replaced perform the following:
16.1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensor.
16.2. Install the old oxygen sensor.
^ Tighten the oxygen sensor to 42 Nm (31 ft. lbs.).
17. If equipped with a 6.0L or 8.1L engine, and the exhaust manifold pipe was not replaced perform the following:
17.1. Connect the oxygen sensor electrical connector.
17.2. Connect the CPA retainer.
17.3. Install the clip around the engine harness and the oxygen sensor pigtail.
18. If equipped with the 4.3L, 4.8L, 5.3L, 6.0L, or 8.1L engines, install the exhaust muffler.





19. Install the oil pan skid plate and bolts, if necessary.
^ Tighten the oil pan skid plate bolts to 20 Nm (15 ft. lbs.).





20. Install the engine shield and bolts, if necessary.
^ Tighten the engine shield bolts to 20 Nm (15 ft. lbs.).
21. Lower the vehicle.