Installation Procedure

When installing exhaust components, inspect the exhaust system for proper alignment. Misaligned components commonly cause rattles, noise and vibrations in the exhaust system. During system alignment, leave all of the bolts or nuts loose, until all of the parts are properly aligned. After properly aligning the parts, tighten the bolts or nuts from the front to the rear.

In order to maintain the alignment of the exhaust system, replace any damaged exhaust system hangers, hanger brackets, and clamps.

Important: 

• Replacement of exhaust system parts must be OEM standard to ensure that the vehicle operates as designed.
• When exhaust system service requires removing and replacing an oxygen sensor, refer to the applicable service procedure.
• Always use new nuts when installing the exhaust pipe to the exhaust manifold.
• Before installing the new nuts, clean the exhaust manifold stud threads with a wire brush.

1. Install the oxygen sensors to the catalytic converter assembly.
2. Install the catalytic converter assembly by doing the following:
   1. 2.1. Raise the catalytic converter assembly into the vehicle, from behind the transfer case support crossmember.
   2. 2.2. Rotate the catalytic converter assembly, while directing the left exhaust pipe between the torsion bar and the transmission.
   3. 2.3. Move the catalytic converter assembly toward the front of the vehicle.
3. Install the collars on the catalytic converter assembly to the exhaust manifold studs (left side). Loosely install the nuts onto the exhaust manifold studs (left side).
   Fig 1: Installing Collars On Catalytic Converter - Left Side (A4WD)

   Courtesy of GENERAL MOTORS CORP.
4. Install the collars on the catalytic converter assembly to the exhaust manifold studs (right side). Loosely install the nuts onto the exhaust manifold studs (right side).
   Fig 2: Installing Collars On Catalytic Converter - Right Side (A4WD)

   Courtesy of GENERAL MOTORS CORP.
5. Connect the catalytic converter assembly and gasket to the muffler assembly.
   Fig 3: Connecting Catalytic Converter Assembly And Gasket To Muffler Assembly (A4WD)

   Courtesy of GENERAL MOTORS CORP.
6. Loosely install the nuts.
7. Connect the catalytic converter assembly hanger to the catalytic converter assembly.
8. Loosely install the catalytic converter assembly hanger to the transfer case.
   Fig 4: Installing Catalytic Converter Assembly Hanger From Transfer Case (A4WD)

   Courtesy of GENERAL MOTORS CORP.
   NOTE: Refer to FASTENER NOTICE in Cautions and Notices.
9. Tighten the exhaust manifold nuts in proper sequence (1-6).

   Tighten 

   • Tighten the catalytic converter assembly-to-exhaust manifold nuts to 53 N.m (39 lb ft).
   • Tighten the catalytic converter assembly hanger-to-transfer case bolts to 55 N.m (41 lb ft).
   • Tighten the catalytic converter assembly-to-muffler assembly nuts to 40 N.m (30 lb ft).
   Fig 5: Exhaust Manifold Nuts Tightening Sequence (A4WD)

   Courtesy of GENERAL MOTORS CORP.
10. Install the 3 oxygen sensor electrical connections and the clips.
    Fig 6: Installing Catalytic Converter Assembly (A4WD)

    Courtesy of GENERAL MOTORS CORP.
11. Remove the support from the catalytic converter assembly.
12. Lower the vehicle.