Catalytic Converter: Service and Repair

Removal
1. Remove the muffler and tail pipe assembly.





2. NOTE: On the 4.2L engine, the two upstream Heated Oxygen Sensors (H02S) are located on the exhaust manifolds and do not need to be removed.

Disconnect the H02S and the catalyst monitor sensor.





3. Remove the nuts.





4. Remove the transfer case skid plate, if equipped.
1 Remove the bolts.
2 Remove the transfer case skid plate.





5. Remove the two bolts retaining the heat shield to the transmission support crossmember bolts.
6. Use a High-Lift jack to support the transmission.





7. Remove the nuts.





8. Remove the transmission support crossmember.
1 Remove the bolts.
2 Remove the transmission support crossmember.





9. On 4.2L or 4.6L engine, remove the nuts.





10. On 5AL engine, remove the nuts.
11. Remove the two TWCs.
1 For 4.2L or 4.6L engine, perform Steps 12 and 13.
2 For 5.4L engine, perform Steps 14 and 15.





12. On 4.2L and 4.6L engine, if only one TWC is being replaced, remove the LH to RH TWC clamp.





13. NOTE: It may be necessary to heat the LH to RH three way catalytic converter joint to ease removal.

Separate the LH and RH TWCs.





14. On 5.4L, engine, if only one TWC is being replaced, remove the clamp.





15. NOTE: It may be necessary to heat the LH to RH three way catalytic converter joint to ease removal.

Separate the LH and RH TWCs.

Installation





1. Insert the LH TWC into the RH TWC.





2. On 5AL engine, insert the LH TWC into the RH TWC.





3. On 5.4L engine, install the pipe clamp.
- Install the nuts.





4. Position the RH and LH TWCs and install the nuts.





5. Install the LH to RH three way catalytic converter pipe clamp.
- Install the two nuts.
- The 4.2L and 4.6L, components are shown; the 5.4L system is similar.





6. On 4.2L and 4.6L engine, install the nuts.





7. On 5.4L engine, install the nuts.





8. Install the transmission support crossmember.
1 Position the transmission support crossmember.
2 Install the bolts.





9. Install the nuts.





10. Install the heat shield to crossmember bolts.
11. Remove the High-Lift Jack.





12. Connect the heated oxygen sensor and the two catalyst monitor sensor electrical connectors.





13. Install the transfer case skid plate.
1 Position the transfer case skid plate.
2 Install the bolts.

14. Install the muffler and tailpipe.