For 1990-2009 cars

## Exhaust Manifold Replacement RPO LSJ

### Removal Procedure

1. Reposition the positive crankcase ventilation (PCV) vent hose clamps (1, 3) at the air cleaner outlet duct and the camshaft cover.
2. Remove the PCV vent hose ends from the outlet duct and cover.
3. Remove the PCV vent tube bolt (4) and nut (5).
4. Remove the PCV vent hose/tube.
5. Remove the exhaust manifold heat shield studs (2).
6. Remove the exhaust manifold heat shield (1).
7. Remove the heated oxygen sensor (HO2S) connector position assurance (CPA) retainer.
8. Disconnect the engine harness electrical connector (1) from the HO2S.
9. Remove the HO2S clip from the bracket on the thermostat housing.
10. Remove the HO2S.
11. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

Notice: Do not bend the exhaust flex decoupler more than 3 degrees in any direction. Movement of more than 3 degrees will damage the exhaust flex decoupler.

12. Remove the catalytic converter to exhaust manifold nuts.
13. Pull down and back on the exhaust pipe in order to separate the catalytic converter from the exhaust manifold.
14. Remove and discard the catalytic converter gasket.
15. Lower the vehicle.
16. Remove the exhaust manifold nuts.
17. Remove the exhaust manifold.
18. Remove and discard the exhaust manifold gasket.
19. Clean and inspect all gasket mating surfaces.

### Installation Procedure

1. Install a NEW exhaust manifold gasket onto the studs.
2. Install the exhaust manifold.

Notice: Refer to Fastener Notice in the Preface section.

3. Install NEW exhaust manifold nuts.

Tighten
Tighten the nuts in the sequence shown to 14 N·m (10 lb ft).

4. Raise and support the vehicle.
5. Install a NEW catalytic converter gasket .
6. Install the catalytic converter to the exhaust manifold studs.
7. Install the catalytic converter to exhaust manifold nuts.

Tighten
Tighten the nuts to 50 N·m (37 lb ft).

8. Lower the vehicle.
9. If reinstalling the old HO2S, coat the threads with anti-seize compound G/M P/N 12377953, or equivalent.
10. Install the HO2S.

Tighten
Tighten the sensor to 30 N·m (22 lb ft).

11. Connect the engine harness electrical connector (1) to the HO2S.
12. Install the HO2S clip to the bracket on the thermostat housing.
13. Install the HO2S CPA retainer.
14. Install the exhaust manifold heat shield (1).
15. Install the exhaust manifold heat shield studs (2).

Tighten
Tighten the studs to 22 N·m (16 lb ft).

16. Install the PCV vent hose/tube.
17. Install the PCV vent tube bolt (4) and nut (5).

Tighten
Tighten the bolt/nut to 10 N·m (89 lb in).

18. Install the PCV vent hose ends to the outlet duct and cover.
19. position the PCV vent hose clamps (1, 3) at the air cleaner outlet duct and the camshaft cover.

## Exhaust Manifold Replacement RPO L61

### Removal Procedure

1. Remove the intake manifold cover. Refer to Intake Manifold Cover Replacement .
2. If equipped with regular production option (RPO) NU3, remove the secondary air injection (AIR) outlet hose/pipe bracket nut.
3. Disconnect the AIR outlet hose/pipe quick connect fitting from AIR check valve. Refer to Plastic Collar Quick Connect Fitting Service .
4. If equipped with RPO NU3, remove the AIR outlet hose/pipe bracket bolt.
5. Remove the AIR outlet hose/pipe bracket from the heat shield stud and reposition the hose/pipe out of the way.
6. Remove the exhaust manifold heat shield studs (2).
7. Remove the exhaust manifold heat shield (1).
8. If equipped with regular production option (RPO) MN5, remove the heated oxygen sensor (HO2S) connector position assurance (CPA) retainer.
9. Disconnect the engine harness electrical connector (2) from the HO2S.
10. Remove the HO2S clip from the thermostat housing.
11. If equipped with RPO M86, remove the HO2S CPA retainer.
12. Disconnect the engine harness electrical connector (1) from the HO2S.
13. Remove the HO2S clip from the thermostat housing.
14. Remove the HO2S.
15. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

Notice: Do not bend the exhaust flex decoupler more than 3 degrees in any direction. Movement of more than 3 degrees will damage the exhaust flex decoupler.

16. Remove the catalytic converter to exhaust manifold nuts.
17. Pull down and back on the exhaust pipe in order to separate the catalytic converter from the exhaust manifold.
18. Remove and discard the catalytic converter gasket.
19. Lower the vehicle.
20. Remove the exhaust manifold nuts.
21. Remove the exhaust manifold.
22. Remove and discard the exhaust manifold gasket.
23. Clean and inspect all gasket mating surfaces.

### Installation Procedure

1. Install a NEW exhaust manifold gasket onto the studs.
2. Install the exhaust manifold.

Notice: Refer to Fastener Notice in the Preface section.

3. Install NEW exhaust manifold nuts.

Tighten
Tighten the nuts in the sequence shown to 14 N·m (10 lb ft).

4. Raise and support the vehicle.
5. Install a NEW catalytic converter gasket .
6. Install the catalytic converter to the exhaust manifold studs.
7. Install the catalytic converter to exhaust manifold nuts.

Tighten
Tighten the nuts to 50 N·m (37 lb ft).

8. Lower the vehicle.
9. If reinstalling the old HO2S, coat the threads with anti-seize compound, or equivalent.
10. Install the HO2S.

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

11. If equipped with RPO M86, connect the engine harness electrical connector (1) to the HO2S.
12. Install the HO2S clip to the thermostat housing.
13. Install the HO2S CPA retainer.
14. If equipped with RPO MN5, connect the engine harness electrical connector (2) to the HO2S.
15. Install the HO2S clip from the thermostat housing.
16. Install the HO2S CPA retainer.
17. Install the exhaust manifold heat shield (1).
18. Install the exhaust manifold heat shield studs (2).

Tighten
Tighten the studs to 22 N·m (16 lb ft).

19. If equipped with RPO NU3, position the AIR hose/pipe and install the bracket onto the heat shield stud.
20. Position the AIR outlet hose/pipe bracket to the cylinder head.
21. Install the AIR outlet hose/pipe bracket bolt.

Tighten
Tighten the bolt to 20 N·m (15 lb ft).

22. Connect the AIR outlet hose/pipe quick connect fitting to AIR check valve. Refer to Plastic Collar Quick Connect Fitting Service .
23. Install the AIR outlet hose/pipe bracket nut.

Tighten
Tighten the nut to 10 N·m (89 lb in).

24. Install the intake manifold cover. Refer to Intake Manifold Cover Replacement .

## Exhaust Manifold Replacement RPO LE5

### Removal Procedure

1. Remove the intake manifold cover. Refer to Intake Manifold Cover Replacement .
2. Remove the exhaust manifold heat shield studs (2).
3. Remove the exhaust manifold heat shield (1).
4. If equipped with regular production option (RPO) MN5, remove the heated oxygen sensor (HO2S) connector position assurance (CPA) retainer.
5. Disconnect the engine harness electrical connector (2) from the HO2S.
6. Remove the HO2S clip from the thermostat housing.
7. If equipped with RPO M86, remove the HO2S CPA retainer.
8. Disconnect the engine harness electrical connector (1) from the HO2S.
9. Remove the HO2S clip from the thermostat housing.
10. Remove the HO2S.
11. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

Notice: Do not bend the exhaust flex decoupler more than 3 degrees in any direction. Movement of more than 3 degrees will damage the exhaust flex decoupler.

12. Remove the catalytic converter to exhaust manifold nuts.
13. Pull down and back on the exhaust pipe in order to separate the catalytic converter from the exhaust manifold.
14. Remove and discard the catalytic converter gasket.
15. Lower the vehicle.
16. Remove the exhaust manifold nuts.
17. Remove the exhaust manifold.
18. Remove and discard the exhaust manifold gasket.
19. Clean and inspect all gasket mating surfaces.

### Installation Procedure

1. Install a NEW exhaust manifold gasket onto the studs.
2. Install the exhaust manifold.

Notice: Refer to Fastener Notice in the Preface section.

3. Install NEW exhaust manifold nuts.

Tighten
Tighten the nuts in the sequence shown to 14 N·m (10 lb ft).

4. Raise and support the vehicle.
5. Install a NEW catalytic converter gasket .
6. Install the catalytic converter to the exhaust manifold studs.
7. Install the catalytic converter to exhaust manifold nuts.

Tighten
Tighten the nuts to 50 N·m (37 lb ft).

8. Lower the vehicle.
9. If reinstalling the old HO2S, coat the threads with anti-seize compound or equivalent.
10. Install the HO2S.

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

11. If equipped with RPO M86, connect the engine harness electrical connector (1) to the HO2S.
12. Install the HO2S clip to the thermostat housing.
13. Install the HO2S CPA retainer.
14. If equipped with RPO MN5, connect the engine harness electrical connector (2) to the HO2S.
15. Install the HO2S clip from the thermostat housing.
16. Install the HO2S CPA retainer.
17. Install the exhaust manifold heat shield (1).
18. Install the exhaust manifold heat shield studs (2).

Tighten
Tighten the studs to 22 N·m (16 lb ft).

19. Install the intake manifold cover. Refer to Intake Manifold Cover Replacement .