Installing Primary Catalytic Converter On Cylinder Bank 1-4

1. Ensure sealing faces of exhaust system are clean.
2. Replace flange gasket -4-  and slide it over the studs on the exhaust manifold -5-  .

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   Ceramic monolith and flange gasket

   1	Primary catalytic converter
   2	Ceramic monolith
   3	Exhaust manifold
   4	Seal
   5	Studs in exhaust manifold

   NOTE: Projecting ceramic catalytic converter 

   • Risk of damage to ceramic catalytic converter 

     → Ensure that your work area is well illuminated.

     → Carefully guide the projecting ceramic catalytic converter past the studs on the exhaust manifold.

     → Cover and store the ceramic monolith for the primary catalytic converter in a safe place until you are ready to install it.

     Protect the ceramic monolith from damage while you are working on the primary catalytic converter. If

     → there are deep cracks or large chips, replace the primary catalytic converter. Slight superficial damage will not impair its function.

3. Carefully move primary catalytic converter into installation position.
4. Fit new fastening nuts between the exhaust manifold and primary catalytic converter, but leave them loose.
5. Make sure that the sheetmetal holder for the primary catalytic converter fits correctly on the exhaust manifold after you tighten the nuts -8-  .
   Fig 1: Holder For Catalytic Converter Components Location - Naturally Aspirated Engine

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   Holder for catalytic converter - naturally aspirated engine

   1	Exhaust manifold, right
   2	Exhaust manifold, left
   3	Seal
   4	Nut
   5	Primary catalytic converter, left
   6	Holder, left
   7	Screw
   8	Holder, right
   9	Primary catalytic converter, right
   10	Bolts between transmission and engine (holder)

6. Fit fastening screw on catalytic converter holder and nuts to the specified tightening torque and according to the specified tightening sequence > Flange bolts securing primary catalytic converter to exhaust manifold  > Tightening torque 23 (17 ftlb.) Nm  > Tightening torque 23 (17 ftlb.) Nm  . For details of tightening torque for transmission screws, see Removing and installing transmission or Removing and mounting transmission.
   Fig 2: Flange Bolts Loosening Sequence

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   Flange bolts securing primary catalytic converter to exhaust manifold

   1 to 5

   Tightening sequence for nuts

   WARNING: Cables not fitted or removed correctly 

   • Risk of burns 
   • Risk of short circuit or fire. 

     → Check for correct fitting.

     → Replace damaged components.

7. Lay oxygen sensor cable and clip it in. -1- 

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   Catalytic converter on naturally aspirated engine (figure shows cylinders 5 to 8)

8. Plug in the connector for the oxygen sensor behind the catalytic converter at the water splash panel.

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.

Fig 1: Holder For Catalytic Converter Components Location - Turbo Engine

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Holder for catalytic converter - turbo engine

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.

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   Placing primary catalytic converter on the studs of the turbocharger

3. Fit side catalytic converter holders.
4. Position new self-locking nuts at the connection points of the catalytic converter and tighten to the specified tightening torque. > Tightening torque 23 (17 ftlb.) Nm 
5. Tighten side catalytic converter holders to the specified tightening torque > Tightening torque 23 (17 ftlb.) Nm  . For details of transmission flange screws, see > 373519 REMOVING AND INSTALLING TRANSMISSION
   WARNING: Cables not fitted or removed correctly 

   • Risk of burns 
   • Risk of short circuit or fire. 

     → Check for correct fitting.

     → Replace damaged components.

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 useful aid here is a piece of wire with a hook.

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   Catalytic converter on turbo engine (figure shows cylinders 1 to 4)

7. Connect the oxygen sensor connectors for the oxygen sensors at the water splash panel and clip the cables into the holders. > Oxygen sensor connectors (figure shows cylinders 1 to 4) 

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Oxygen sensor connectors (figure shows cylinders 1 to 4)