Exhaust System

Exhaust System-3.9L





Special Tool(s)





Material

WARNING: The normal operating temperature of the exhaust system is very high. Never attempt to repair or install any new part of the system until it has cooled. Be especially careful when working around the three-way catalytic converter. The temperature of the three-way catalytic converter rises to a high level after only a few minutes of engine operation.

CAUTION: Do not use oil or grease-based lubricants on the isolators. They may cause deterioration of the rubber.

CAUTION: Oil or greased-based lubricants on the isolators may cause the exhaust hanger isolator to separate from the exhaust hanger bracket during vehicle operation.

NOTE: Exhaust fasteners are of a torque prevailing design. Use only new fasteners with the same part number as the original. Torque values must be used as specified during reassembly to make sure of correct retention of exhaust components.

1. With the vehicle in NEUTRAL, position it on a hoist.





2. Using a suitable jackstand, support the exhaust pipes at the rear of the resonators.

3. CAUTION: Use caution removing the catalytic converter. Make sure not to damage the manifold outlet flare, the converter inlet flare or the studs.

Support the catalytic converter near the rear outlet.





4. NOTE: The isolators should not be reused. If the exhaust system is removed from the vehicle, install new isolators.

Remove the exhaust hanger bracket and the exhaust hanger isolator as an assembly.
^ To install, tighten to 30 Nm (22 ft. lbs.).





5. If necessary, remove the heat shield bolts and nuts and the heat shield.
^ To install, tighten to 10 Nm (89 inch lbs.).
6. Disconnect the heated oxygen sensor electrical connector.
7. Disconnect the catalyst monitor sensor electrical connector.
8. Remove the manifold-to-converter flange stud nuts and the converter assembly.
^ To install, tighten to 40 Nm (30 ft. lbs.).





9. If necessary, using the special tool, remove the catalyst monitor sensors.

NOTE: Apply anti-seize to the sensor threads before installation.

To install, tighten to 41 Nm (30 ft. lbs.).





10. If necessary, using the special tool, remove the oxygen sensors.

NOTE: Apply anti-seize to the sensor threads before installation.

^ To install, tighten to 41 Nm (30 ft. lbs.).
11. If necessary, remove the manifold-to-converter flange studs.
^ To install, tighten to 40 Nm (30 ft. lbs.).
12. To install, reverse the removal procedure.

13. NOTE: Clean the mating surfaces of the manifold outlet flare and the catalytic converter inlet flare. Support the catalytic converter near the rear outlet. Make sure not to damage the manifold outlet flare, the converter inlet flare or the studs. To correctly seat the converter, alternately tighten the exhaust manifold-to-catalytic converter nuts to specification.

Check and, if necessary, align the exhaust system.