Engine Exhaust System: Removal & Installation GMC Acadia I

Removal Procedure

1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side»(ref-365262-S00919450402010070600000) .
2. Remove the oil level indicator. Refer to «Oil Level Indicator Tube Replacement»(ref-365266-S02574245452010070600000) .
3. Remove the catalytic converter. Refer to «Catalytic Converter Replacement - Left Side»(ref-365262-S12138154182010070600000) .
4. Remove the exhaust manifold bolts (1).
5. Remove the exhaust manifold and gasket. Discard the gasket.
6. Remove the heated oxygen sensor (1) from the exhaust manifold.

Installation Procedure

Note. A special anti-seize compound is used in the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
2. Install the HO2S (1) to the exhaust manifold. Tighten: Tighten the sensor to 42 N.m (31 lb ft).
3. Install one exhaust manifold bolt (1) to the exhaust manifold.
4. Install the NEW exhaust manifold gasket onto the exhaust manifold and bolt.
5. Install the exhaust manifold (with gasket) to the cylinder head and the catalytic converter.
6. Install the remaining exhaust manifold bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
7. Install the catalytic converter. Refer to «Catalytic Converter Replacement - Left Side»(ref-365262-S12138154182010070600000) .
8. Install the oil level indicator. Refer to «Oil Level Indicator Tube Replacement»(ref-365266-S02574245452010070600000) .
9. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side»(ref-365262-S00919450402010070600000) .

1. Remove the catalytic converter. Refer to «Catalytic Converter Replacement - Right Side»(ref-365262-S36212106482010070600000) .
2. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Right Side»(ref-365262-S22599963682010070600000) .
3. Remove the exhaust manifold bolts (1).
4. Remove the exhaust manifold and gasket out from vehicle. Discard the gasket.

1. Install one exhaust manifold bolt (1) to the exhaust manifold.
2. Install the NEW exhaust manifold gasket onto the cylinder head and bolt.
3. Install the exhaust manifold (with gasket) to the catalytic converter and the cylinder head.
4. Install the exhaust manifold bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
5. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Right Side»(ref-365262-S22599963682010070600000) .
6. Install the catalytic converter. Refer to «Catalytic Converter Replacement - Right Side»(ref-365262-S36212106482010070600000) .

1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side»(ref-365262-S00919450402010070600000) .
2. Remove the catalytic converter to exhaust manifold nuts (1).
3. Remove the exhaust flexible pipe. Refer to «Exhaust Flexible Pipe Replacement»(ref-365262-S25119686372010070600000) .
4. Remove the catalytic converter brace bolt (2).
5. Remove the catalytic converter from the exhaust manifold.
6. Remove and discard the catalytic converter to exhaust manifold seal (1).

1. Install a NEW exhaust manifold seal (1) onto the catalytic converter.
2. Install the catalytic converter to the exhaust manifold.
3. Install the catalytic converter brace bolt (2). Tighten: Tighten the bolt to 50 N.m (37 lb ft).
4. Install the exhaust flexible pipe. Refer to «Exhaust Flexible Pipe Replacement»(ref-365262-S25119686372010070600000) .
5. Install the catalytic converter to exhaust manifold nuts (1). Tighten: Tighten the nuts to 50 N.m (37 lb ft).
6. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side»(ref-365262-S00919450402010070600000) .

1. If equipped with all wheel drive (AWD), remove the transfer case. Refer to «TRANSFER CASE ASSEMBLY REPLACEMENT»(ref-365299-S27472254222010070600000) .
2. Remove the exhaust flexible pipe. Refer to «Exhaust Flexible Pipe Replacement»(ref-365262-S25119686372010070600000) .
3. Remove the catalytic converter to exhaust manifold nuts (2).
4. Remove the catalytic converter from the exhaust manifold.
5. Remove and discard the catalytic converter to exhaust manifold seal (1).

1. Install a NEW catalytic converter to exhaust manifold seal (1) onto the catalytic converter.
2. Install the catalytic converter to the exhaust manifold.
3. Install the catalytic converter to exhaust manifold nuts (2). Tighten: Tighten the nuts to 50 N.m (37 lb ft).
4. If equipped with all wheel drive (AWD), install the transfer case. Refer to «TRANSFER CASE ASSEMBLY REPLACEMENT»(ref-365299-S27472254222010070600000) .
5. Install the exhaust flexible pipe. Refer to «Exhaust Flexible Pipe Replacement»(ref-365262-S25119686372010070600000) .

Scheme 1

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-365243-S07204316382010070600000) .
2. Remove the three way catalytic converter to muffler pipe nuts (1).
3. With the aid of an assistant, separate the rubber insulators from the exhaust underbody hangers (1).
4. With the aid of an assistant, remove the muffler assembly from exhaust flexible pipe and the vehicle.

1. With the aid of an assistant, install the muffler assembly to the vehicle and the exhaust flexible pipe.
2. With the aid of an assistant, install the rubber insulators to the exhaust underbody hangers (1).
3. Install the three way catalytic converter to muffler piper nuts (1) and tighten to 50 N.m (37 lb ft).
4. Lower the vehicle.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-365243-S07204316382010070600000) .
2. Remove the three way catalytic converter to muffler pipe nuts (1).
3. With the aid of an assistant, separate the rubber insulators from the exhaust underbody hangers (1, 2, and 3).
4. With the aid of an assistant, remove the muffler assembly from exhaust flexible pipe and the vehicle.

1. With the aid of an assistant, install the muffler assembly to the vehicle and the exhaust flexible pipe.
2. With the aid of an assistant, install the rubber insulators to the exhaust underbody hangers (1, 2, and 3).
3. Install the three way catalytic converter to muffler pipe nuts (1) and tighten to 50 N.m (37 lb ft).
4. Lower the vehicle.

Scheme 2

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-365243-S07204316382010070600000) .
2. Remove the exhaust manifold lower heat shield bolts (1, 2).
3. Remove the exhaust manifold lower heat shield.

1. Position the exhaust manifold lower heat shield to the engine.
2. Install the exhaust manifold lower heat shield bolts (1, 2). Tighten bolt (1) to 10 N.m (89 lb in) and tighten bolt (2) to 50 N.m (37 lb ft).
3. Lower the vehicle.

1. Remove the heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(ref-365256-S18468095462010070600000) .
2. Remove the exhaust flexible pipe. Refer to «Exhaust Flexible Pipe Replacement»(ref-365262-S25119686372010070600000) .
3. Remove the exhaust manifold heat shield bolts (1).
4. Remove the exhaust manifold heat shield.

1. Install the exhaust manifold heat shield.
2. Install the exhaust manifold heat shield bolts (1) and tighten to 10 N.m (89 lb in).
3. Install the exhaust flexible pipe. Refer to «Exhaust Flexible Pipe Replacement»(ref-365262-S25119686372010070600000) .
4. Install the HO2S. Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(ref-365256-S18468095462010070600000) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(ref-365266-S26720386232010070600000) .
2. Disconnect the engine wiring harness electrical connector (2) from the heated oxygen sensor (HO2S) electrical connector (3).
3. Remove the HO2S electrical connector retainer from the engine wiring harness clip (1).
4. Remove the exhaust manifold heat shield bolts (1).
5. Remove the exhaust manifold heat shield, sliding the shield up over the HO2S pigtail.

1. Install the exhaust manifold heat shield, sliding the shield down over the HO2S pigtail.
2. Install the exhaust manifold heat shield bolts (1) and tighten to 10 N.m (89 lb in).
3. Connect the engine wiring harness electrical connector (2) to the HO2S electrical connector (3).
4. Install the HO2S electrical connector retainer to the wiring harness clip (1).
5. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(ref-365266-S26720386232010070600000) .

1. Remove the muffler assembly. Refer to «Exhaust Muffler Replacement (With NB5)»(ref-365262-S35396637962010070600000) or «Exhaust Muffler Replacement (With NEA,NEB or N10)»(ref-365262-S24106472052010070600000) .
2. Remove the exhaust muffler front heat shield nuts (3).
3. Remove the exhaust muffler front heat shield (4).
4. Remove the exhaust muffler heat shield nuts (1).
5. Remove the exhaust muffler heat shield (2).

1. Position the exhaust muffler heat shield (2) to the floor panel.
2. Install the exhaust muffler heat shield nuts (1). Tighten: Tighten the nuts to 9 N.m (80 lb in).
3. Position the exhaust muffler front heat shield (4) to the floor panel.
4. Install the exhaust muffler front heat shield nuts (3). Tighten: Tighten the nuts to 9 N.m (80 lb in).
5. Install the muffler assembly. Refer to «Exhaust Muffler Replacement (With NB5)»(ref-365262-S35396637962010070600000) or «Exhaust Muffler Replacement (With NEA,NEB or N10)»(ref-365262-S24106472052010070600000) .