Catalytic Converter: Service and Repair
WM 267619 Removing and installing primary catalytic converter
Technical values
Preliminary work
1. Move front lid to service position. -> 552213 Securing lid (service position) Procedures
2. Remove front underbody panelling -> 519219 Removing and installing cover for front underbody - section on "Removing" 519219 Removing and installing Cover For Front Underbody.
Removing primary catalytic converter
Removing primary catalytic converter on right side
CAUTION
Hot components
- Risk of burns
-> Let hot components cool down.
-> Wear personal protective gear.
CAUTION
Heavy components
- Risk of squashing
-> Wear personal protective gear.
-> Get someone to help if necessary.
Component overview
1. Detach engine wire harness from the bulkhead on the right side. For details, see partial work in scope -> 508119 Removing and installing cross panel (disassembling plenum panel) - section on "Removing" Service and Repair. This makes it easier to access the oxygen sensor cable.
1.1. Detach cowl panel cover on the right side.
1.2. Lift engine wire harness out of the bulkhead on the right side.
2. Remove electric plug-in connectors -1- from the oxygen sensors.
Pulling off connectors
3. Check that the cables are routed correctly => Cable routing !
Cable routing
4. Unclip cable on the right cylinder bank.
5. Raise the vehicle -> 4X00IN Lifting the vehicle Service and Repair.
6. Unclip cable at the transmission housing.
7. Pull oxygen sensor cables downwards.
7.1. Fasten the cables to a suitable cord so that you can pull them up again during installation.
7.2. Pull the cables down past the vacuum pump.
8. Loosen clamping sleeves -1- for the exhaust pipe.
Loosening clamps
8.1. Loosen clamping screws -2-.
8.2. Slide clamping sleeves towards the rear -arrow-.
9. Screw off fastening nut -1- on the bottom holder -2-.
Mounting for bottom holder
10. Unscrew fastening screw -1- on top holder -2-.
Top holder
11. Screw off fastening nuts on studs -3-.
12. Remove primary catalytic converter.
Removing primary catalytic converter on left side
Information
- The procedure for removing and installing the left primary catalytic converter is essentially the same as for the right side.
Component overview
1. Remove electric plug-in connectors -1- from the oxygen sensors.
Pulling off connectors
2. Check that the oxygen sensor cables are routed correctly => Oxygen sensor cable routing !
Oxygen sensor cable routing
3. Unclip cable on the left cylinder bank.
4. Raise the vehicle -> 4X00IN Lifting the vehicle Service and Repair.
5. Unclip cable at the transmission housing => Oxygen sensor cable routing.
6. Pull oxygen sensor cables downwards.
6.1. Fasten the cables to a suitable cord so that you can pull them up again during installation.
6.2. Pull the cables down past the high-pressure pump.
7. Loosen clamping sleeves -1- for the exhaust pipe.
Loosening clamps (diagram)
7.1. Loosen clamping screws -2-.
7.2. Slide clamping sleeves towards the rear -arrow-.
8. The procedure for removing the left primary catalytic converter from the holders is the same as for the right side.
Installing primary catalytic converter
Installing primary catalytic converter on right side
Information
- The primary catalytic converters are installed in reverse order to removal.
- The primary catalytic converters must be installed upwards on the manifold flange with the least possible tolerance (check the distance from the rear exhaust pipe to the tunnel bridge).
- The fastening nuts on the studs for the manifold must be tightened in diagonally opposite sequence.
Component overview
1. Replace seals and nuts.
2. Use new clamping sleeves and slide them onto the exhaust pipes.
3. Before finally screwing the primary catalytic converter to the exhaust manifold, adjust the primary catalytic converter so that there is sufficient space between the exhaust system and adjacent components. =>
3.1. When fitting the primary catalytic converter onto the studs on the exhaust manifold, press the primary catalytic converter up fully and tighten the lower nut first (this prevents it from slipping down). Get a second mechanic to help if necessary.
4. Fit the three remaining fastening nuts between the primary catalytic converter and exhaust manifold and tighten all nuts to the specified tightening torque.
5. Fit the front holder.
6. Move (lift) the exhaust system to the same height as the two exhaust pipes on the primary catalytic converters. Check that the exhaust pipes are parallel.
7. Move the clamping sleeves evenly into installation position and screw them on.
8. Press the exhaust system up slightly and fit the rear holder for the transmission. Get a second mechanic to help if necessary.
9. Tighten all holders, fastening screws and nuts to => Tightening torque: 23 Nm (17 ftlb.).
10. Check adjustment and distance from the exhaust system (pipe) to the tunnel bridge =>
Exhaust system and tunnel bridge
10.1. Place a steel rule between the upper edge of the tunnel bridge and the exhaust pipe. Minimum distance: 15 mm. The distance must never be less than this value (risk of contact and humming noises). Optimum distance: 17 to 20 mm.
Measuring the distance
Installing primary catalytic converter on left side
Information
- The primary catalytic converters are installed in reverse order to removal.
- The primary catalytic converters must be installed upwards on the manifold flange with the least possible tolerance (check the distance from the rear exhaust pipe to the tunnel bridge).
- The fastening nuts on the studs for the manifold must be tightened in diagonally opposite sequence.
Component overview
1. Replace seals and nuts.
2. Use new clamping sleeves and slide them onto the exhaust pipes.
3. Before finally screwing the primary catalytic converter to the exhaust manifold, adjust the primary catalytic converter so that there is sufficient space between the exhaust system and adjacent components. =>
3.1. When fitting the primary catalytic converter onto the studs on the exhaust manifold, press the primary catalytic converter up fully and tighten the lower nut first (this prevents it from slipping down). Get a second mechanic to help if necessary.
4. Fit the three remaining fastening nuts between the primary catalytic converter and exhaust manifold and tighten all nuts to the specified tightening torque.
5. Fit the front holder.
6. Move (lift) the exhaust system to the same height as the two exhaust pipes on the primary catalytic converters. Check that the exhaust pipes are parallel.
7. Move the clamping sleeves evenly into installation position and screw them on.
8. Press the exhaust system up slightly and fit the rear holder for the transmission. Get a second mechanic to help if necessary.
9. Tighten all holders, fastening screws and nuts to => Tightening torque: 23 Nm (17 ftlb.).
10. Check adjustment and distance from the exhaust system (pipe) to the tunnel bridge =>
Exhaust system and tunnel bridge
10.1. Place a steel rule between the upper edge of the tunnel bridge and the exhaust pipe. Minimum distance: 15 mm. The distance must never be less than this value (risk of contact and humming noises). Optimum distance: 17 to 20 mm.
Measuring the distance
Subsequent work
1. Install front underbody panelling. -> 519219 Removing and installing cover for front underbody - section on "Installing" 519219 Removing and installing Cover For Front Underbody