Catalytic Converter: Service and Repair

Catalytic Converter - 4.6L, 5.4L








Removal and Installation
1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Maintenance/Service and Repair.

2. CAUTION: When repairing the exhaust system or removing exhaust components, disconnect all heated oxygen sensors (HO2S) and catalyst monitor sensors at the wiring connectors to prevent damage to the sensors and wiring harnesses.

Disconnect the RH HO2S electrical connector.





3. Using a jackstand, support the muffler.
4. Loosen the 2 exhaust couplers and disconnect the intermediate pipes from the catalytic converter assembly. Discard the exhaust couplers.
^ To install, tighten to 48 Nm (35 lb-ft).
^ Alternately tighten, in 10 Nm (89 lb-in) increments.
5. Disconnect the RH and LH catalyst monitor sensor electrical connectors.





6. NOTE: Hand-tighten all the catalytic converter nuts.

Remove and discard the 2 RH catalytic converter-to-exhaust manifold nuts.
^ To install, tighten to 40 Nm (30 lb-ft).





7. Remove and discard the 2 LH catalytic converter-to-exhaust manifold nuts.
^ To install, tighten to 40 Nm (30 lb-ft).





8. NOTE: Make sure not to damage the manifold outlet flare, the converter inlet flare or the studs.

Remove the catalytic converter assembly.





9. Remove and discard the 4 catalytic converter-to-exhaust manifold studs.
^ To install, tighten to 40 Nm (30 lb-ft).

10. NOTE: Using a Scotch Brite(R) pad, clean the mating surfaces of the manifold outlet flare and the catalytic converter inlet flare, at the catalytic converter outlet flare and the muffler inlet pipe. Keep foreign materials out of the catalytic converters.

NOTE: Using a jackstand, support the catalytic converter near the rear outlet while positioning the converter into place. Align the manifold studs into the pipe flange. Make sure not to damage the studs or mating surfaces.

^ Make sure to correctly align the catalytic converter to the exhaust manifold before installing the fasteners. The catalytic converter is correctly positioned when the hanger rods are centered in the isolators.
To install, reverse the removal procedure.
^ Always install new converter-to-manifold nuts, studs and exhaust couplers.