Catalytic Converter: Service and Repair
Catalytic Converter - 4.6L, 5.4LRemoval and Installation
1. With the vehicle in NEUTRAL, position it on a hoist.
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.
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 45 Nm (33 ft. lbs.).
^ Starting with the upper nut, alternately tighten, in 10 Nm (89 inch lbs.) increments, the RH catalytic converter-to-exhaust manifold nuts to specification.
7. Remove and discard the 2 LH catalytic converter-to-exhaust manifold nuts.
- To install, tighten to 45 Nm (33 ft. lbs.).
^ Starting with the upper nut, alternately tighten, in 10 Nm (89 inch lbs.) increments, the LH catalytic converter-to-exhaust manifold nuts to specification.
8. NOTE: Make sure not to damage the manifold outlet flare, the converter inlet flare or the studs.
Remove the catalytic converter assembly.
9. NOTE: Using a Scotch Brite� pad, clean the mating surfaces of the manifold outlet flare, 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 and exhaust couplers.