Removing and Installing Primary Catalytic Converter

Removing And Installing Primary Catalytic Converter On 4.8-litre V8 DFI Engines

Technical values







Preliminary work

Preliminary work for removing primary catalytic converter on cylinder bank 1-4
1. Remove wheel
2. Remove engine compartment cover above the oxygen sensor connectors.
3. Remove main catalytic converter.

Preliminary work for removing primary catalytic converter on cylinder bank 5-8
1. Remove engine compartment cover above the oxygen sensor connectors.
2. Remove main catalytic converter.

Removing primary catalytic converter

Removing primary catalytic converter on cylinder bank 1-4

CAUTION:
Danger of burns from hot exhaust system
- Do not remove the exhaust system until it has cooled down.
- Wear protective gloves.












1. Disconnect the oxygen sensor connectors for the oxygen sensors on the catalytic converter at the water splash panel (follow cable routing) and unclip the cables from the holders.







2. Route the oxygen sensor cables to the catalytic converter. -1-

INFORMATION: Spray all fastening nuts on primary catalytic converter with penetrating oil and allow to work in.







3. Screw off hexagon-head bolt on the side catalytic converter holder -arrow-. Use a narrow fine-tooth ratchet to do this.
4. Carefully pull the oxygen sensor cable down.

INFORMATION:
- To loosen and tighten fastening nuts on flange of turbocharger, several extensions and joints must be used.
- Good lighting and a mirror make removal and fitting easier at places very difficult to reach.







5. Loosen the five fastening nuts on the turbocharger.
6. Remove primary catalytic converter. To do this, carefully turn and pull the primary catalytic converter.
7. Remove and replace flange gaskets.

Removing primary catalytic converter on cylinder bank 5-8

CAUTION:
Danger of burns from hot exhaust system
- Do not remove the exhaust system until it has cooled down.
- Wear protective gloves.












1. Disconnect the oxygen sensor connectors for the oxygen sensors on the catalytic converter at the water splash panel (follow cable routing) and unclip the cables from the holders.







2. Route the oxygen sensor cables to the catalytic converter. -1-







3. Remove the heat shield on the steering gear connection. To do this, loosen the fastening screws.

INFORMATION: Spray all fastening nuts on primary catalytic converter with penetrating oil and allow to work in.







4. Screw off hexagon-head bolt on the side catalytic converter holder -arrow- and carefully pull oxygen sensor cable through in a downward direction.

INFORMATION:
- To loosen and tighten fastening nuts on flange of turbocharger, several extensions and joints must be used.
- Good lighting and a mirror make removal and fitting easier at places very difficult to reach.







5. Loosen the five fastening nuts on the turbocharger.
6. Remove primary catalytic converter. To do this, carefully turn and pull the primary catalytic converter. Move the steering if necessary and pull the primary catalytic converter past it.
7. Remove and replace flange gasket.

Installing primary catalytic converter

Installing primary catalytic converter on cylinder bank 1-4







1. Replace flange gasket and push over the studs.







2. Place primary catalytic converter on the studs of the turbocharger. To do this, carefully turn and push the primary catalytic converter into installation position.
3. Position hexagon-head bolt of side holder for catalytic converter. To do this, use a narrow fine-tooth ratchet.

INFORMATION:
- To loosen and tighten fastening nuts on flange of turbocharger, several extensions and joints must be used.
- Good lighting and a mirror make removal and fitting easier at places very difficult to reach.

4. Fit new self-locking nuts at the catalytic converter connection points and tighten to the specified torque. - Tightening torque: 23 Nm (17 ftlb.)
5. Tighten the hexagon-head bolt on the side catalytic converter holder to the specified tightening torque. Use a narrow fine-tooth ratchet to do this. - Tightening torque: 23 Nm (17 ftlb.)

CAUTION:
Danger of fire and material damage.
- Lay the oxygen sensor cable so that it cannot touch the exhaust manifold.







6. Route oxygen sensor cables upwards so that the oxygen sensor cables are not touching the exhaust manifold or the exhaust system and clip them into position -1-. A piece of wire with a hook on it is very useful here.







7. Connect the oxygen sensor connectors for the oxygen sensors at the water splash panel and clip the cables into the holders.

Installing primary catalytic converter on cylinder bank 5-8







1. Replace flange gasket and push over the studs of the turbocharger.







2. Position the primary catalytic converter on the bolts on the turbocharger. To do this, carefully turn and pull the primary catalytic converter. Move the steering if necessary and move the primary catalytic converter into installation position.
3. Position hexagon-head bolt of side holder for catalytic converter.

INFORMATION:
- To loosen and tighten fastening nuts on flange of turbocharger, several extensions and joints must be used.
- Good lighting and a mirror make removal and fitting easier at places very difficult to reach.

4. Fit new self-locking nuts at the connection points for the primary catalytic converter and tighten to the specified torque. - Tightening torque: 23 Nm (17 ftlb.)
5. Tighten the hexagon-head bolt on the side catalytic converter holder to the specified tightening torque. - Tightening torque: 23 Nm (17 ftlb.)







6. Fit the heat shield on the steering gear connection. To do this, fit the fastening screws. - Tightening torque: 10 Nm (7.5 ftlb.)

CAUTION:
Danger of fire and material damage.
- Lay the oxygen sensor cable so that it cannot touch the exhaust manifold.







7. Route oxygen sensor cables upwards so that the oxygen sensor cables are not touching the exhaust manifold or the exhaust system and clip them into position -1-. A piece of wire with a hook on it is very useful here.







8. Connect the oxygen sensor connectors for the oxygen sensors at the water splash panel and clip the cables into the holders.

Subsequent work

Subsequent work for installing primary catalytic converter on cylinder bank 1-4
1. Install main catalytic converter.
2. Fit engine compartment cover above the oxygen sensor connectors.

Subsequent work for installing primary catalytic converter on cylinder bank 5-8
1. Install main catalytic converter.
2. Fit engine compartment cover above the oxygen sensor connectors.