Twin catalytic converters replacement

Good morning.

This is best done with a lift as access is better from the bottom.

The procedure below as well as pictures.

Book time is 2.5 hours.

Roy

Three-way catalytic converter (TWC), replacing

Special tools:
999 5543 SOCKET NV-22 HO2S See: Vehicle > Electrical / Mechanical Repair > 999 5543 Socket NV-22 HO2S
999 5972 FIXTURE See: Vehicle > Electrical / Mechanical Repair > 999 5972 Fixture

Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information in the illustrations is always correct.

Preparation

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Remove the splash guard from under the engine.

Remove:
- the connectors for the heated oxygen sensors (HO2S)
- the wiring for the heated oxygen sensors (HO2S) from the mountings
- the screw for the mounting for the engine stabilizer brace on the engine
- the engine stabilizer brace between the suspension turrets
- the plastic charge air pipe. Place to one side
- the plastic intake pipe. Put it to one side.

Removing components

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Remove:
- the intake and charge air pipes from turbocharger (TC)
- the heat deflector plates
- the upper heated oxygen sensors (HO2S)
- the expansion tank cap.

Removing three-way catalytic converters (TWC) / front exhaust pipe

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Remove:
- the nuts. Disconnect the front exhaust pipe from the turbocharger (TC)
- the nuts where the exhaust pipe divides downstream of the three-way catalytic converter (TWC)
- the center SIPS member.
Disconnect the brake pipe from the clips on the front SIPS member.
Remove the screws from the front SIPS member.
Slide the three-way catalytic converter (TWC) (with the heat deflector plate) back and then lower it.

Note! For tightening torques, see: Tightening torque See: Engine > Mechanical > Tightening Torque.

Note! To ensure that there is no exhaust leakage, see: Flanged joint, assembling See: Exhaust Pipe > Removal and Replacement > Flanged Joint, Assembling.

Transferring components

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Transfer:
- the SIPS member with the exhaust system mountings
- heated oxygen sensors (HO2S).
Lubricate the heated oxygen sensors (HO2S). Tighten the heated oxygen sensors (HO2S). See: Tightening torque See: Engine > Mechanical > Tightening Torque. Use tool 999 5543 SOCKET NV-22 HO2S See: Vehicle > Electrical / Mechanical Repair > 999 5543 Socket NV-22 HO2S.

Okay, when the downstream O2 voltage is the same as the upstream voltage, that is when the catalytic converters are not doing their job anymore and need to be replaced.

Those readings indicate a bad catalytic converter.

Roy

You are welcome.

Roy