Installation Procedure

Install the rear exhaust hanger brackets to the rear exhaust hangers.
NOTE: Refer to FASTENER NOTICE in Cautions and Notices.
Install the 2 nuts securing the rear exhaust hangers to the rear exhaust hanger brackets.
Tighten

Tighten the rear exhaust hanger nuts to 30 N.m (22 lb ft).

Fig 1: Installing Rear Exhaust Hanger Brackets To Rear Exhaust Hangers
Courtesy of GENERAL MOTORS CORP.

NOTE: Refer to EXHAUST SYSTEM INSPECTION NOTICE in Cautions and Notices.
Place a NEW catalytic converter gasket over the catalytic converter studs.
NOTE: Refer to FLEX DECOUPLER NOTICE in Cautions and Notices.
With the aid of an assistant, raise the exhaust system into position, aligning the catalytic converter with the rear exhaust manifold pipe.
Finger tighten the 4 nuts to the catalytic converter studs.

Fig 2: Installing Catalytic Converter To Rear Exhaust Manifold Pipe
Courtesy of GENERAL MOTORS CORP.
Install the 2 bolts securing the rear exhaust hanger brackets to the rear compartment rails.
Tighten

Tighten the rear exhaust hanger bolts to 50 N.m (37 lb ft).

Fig 3: Installing Bolts Securing Rear Exhaust Hanger Brackets To Rear Compartment Rails
Courtesy of GENERAL MOTORS CORP.
Install the 2 bolts securing the center exhaust hangers to the rear suspension support brackets.
Tighten

Tighten the center exhaust hanger bolts to 30 N.m (22 lb ft).
Tighten the 4 catalytic converter nuts previously installed in step 5.
Tighten

Tighten the catalytic converter nuts to 25 N.m (18 lb ft).
Install the heated oxygen sensor. Refer to HEATED OXYGEN SENSOR in Engine Controls-4.6L.
Remove the oxygen sensor wiring harness heat shield. Refer to OXYGEN SENSOR WIRING HARNESS HEAT SHIELD REPLACEMENT .
Lower the vehicle.

Fig 4: Installing Bolts Securing Center Exhaust Hangers To Rear Suspension Support Brackets
Courtesy of GENERAL MOTORS CORP.