Hummer H2. Manual - part 1899

Fig. 17: Exhaust Manifold Pipe Nuts (Right) 
Courtesy of GENERAL MOTORS CORP. 

5. Install the exhaust manifold pipe nuts. 

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

NOTE:

Refer to Fastener Notice in Cautions and Notices.

 

2004 Hummer H2 

2004 ENGINE Engine Exhaust - Hummer H2

  

Fig. 18: View Of O2 Sensor Harness 
Courtesy of GENERAL MOTORS CORP. 

6. If the exhaust manifold pipe was replaced perform the following: 

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

sensor.  

2. Install the old oxygen sensor. 

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

7. If the exhaust manifold pipe was not replaced perform the following: 

1. Connect the oxygen sensor electrical connector.  

2. Connect the CPA retainer.  

 

2004 Hummer H2 

2004 ENGINE Engine Exhaust - Hummer H2

  

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

8. Install the exhaust muffler. Refer to Muffler Replacement .  

9. Install the engine protection shield. Refer to Engine Protection Shield Replacement in Frame and 

Underbody. 

Tighten: Tighten the bolts to 20 N.m (15 lb ft). 

10. Lower the vehicle.  

EXHAUST SEAL REPLACEMENT 

Removal Procedure 

1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. 

2. Remove the engine protection shield. Refer to Engine Protection Shield Replacement in Frame and 

Underbody. 

 

2004 Hummer H2 

2004 ENGINE Engine Exhaust - Hummer H2

  

Fig. 19: View Of Transmission 
Courtesy of GENERAL MOTORS CORP. 

3. Disconnect the CPA retainer.  

4. Disconnect the oxygen sensor electrical connector (1).  

5. Support the catalytic converter or exhaust manifold pipe with adjustable jackstands. 

 

2004 Hummer H2 

2004 ENGINE Engine Exhaust - Hummer H2