Exhaust Manifold: Service and Repair

Exhaust Manifold Replacement (RPO LE5)

Removal Procedure





1. Remove the intake manifold cover. Refer to Intake Manifold Cover Replacement (Service and Repair) .
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 .

3. Install NEW exhaust manifold nuts.

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 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, Saturn P/N 21485279 or equivalent.
10. Install the HO2S.

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

19. Install the intake manifold cover. Refer to Intake Manifold Cover Replacement (Service and Repair) .