Exhaust Manifold Pipe Replacement 6.0L, 6.6L, and 8.1L Engines

1. Depending on which side is being replaced, perform one of the following steps:

•	Remove the exhaust muffler nuts.

•

or

•	Loosen the exhaust pipe clamp.

2. Remove the necessary exhaust system hangers so that the pipes can be separated.
3. Use a jack stand to support the exhaust.



4. If equipped with a 6.0L or 8.1L engine, perform the following:

4.1.	Remove the clip around the engine harness and the oxygen sensor pigtail.

4.2.	Disconnect the connector position assurance (CPA) retainer.

4.3.	Disconnect the oxygen sensor electrical connector.

4.4.	If replacing the exhaust manifold pipe, remove the oxygen sensor.




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



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



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



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



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

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 or 8.1L engine, 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 the 6.6L engine, install the exhaust muffler nuts until snug.

Notice: Refer to Fastener Notice in the Preface section.





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

9. If equipped with a 6.6L engine, slide the exhaust pipe clamp down and around the pipe connection.
10. Tighten the exhaust pipe clamp and muffler nuts.

Tighten

•	Tighten the clamp to 40 N·m (30 lb ft).

•	Tighten the nuts to 40 N·m (30 lb ft).




11. If equipped with a 6.0L or 8.1 L engine, install the exhaust manifold pipe nuts.

Tighten
Tighten the nuts to 50 N·m (39 lb ft).




12. If equipped with a 6.0L or 8.1L engine, and the exhaust manifold pipe was replaced perform the following:

12.1.

Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensor.

12.2.

Install the old oxygen sensor.

Tighten
Tighten the oxygen sensor to 42 N·m (31 lb ft).

13. If equipped with a 6.0L or 8.1L engine, and the exhaust manifold pipe was not replaced perform the following:

13.1.

Connect the oxygen sensor electrical connector.

13.2.

Connect the CPA retainer.

13.3.

Install the clip around the engine harness and the oxygen sensor pigtail.

14. Install the exhaust pipe/catalytic converter to the vehicle.
15. Install the exhaust system hangers.



16. Depending on which side is being replaced, perform one of the following steps:

•	Install the exhaust muffler nuts.

Tighten
Tighten the nuts to 40 N·m (30 lb ft).

•

or

•	Install a NEW exhaust pipe clamp.

Tighten
Tighten the clamp to 44 N·m (33 lb ft).