Exhaust Pipe: Service and Repair

Front Exhaust Pipe with Catalytic Converters and Front Muffler

Removing

- Remove the engine cover - arrows -.






- Remove the bolts - arrows - and air guide.






- Remove both the lower air guide and the air guide hose.

- Disconnect the connector - 1 - from the Mass Airflow (MAF) sensor (G70).






- Remove the air guide hose - 2 -.

- Remove the bolt - 4 - and the air filter housing.

• Ignore - 3 -.

- Remove the air guide pipe bolt - arrow -.






- Remove the air guide pipe; to do this, loosen the hose clamp - 1 -.

- Press the release buttons and remove the air guide hose - 2 -.

- Disconnect the electrical wire connector - arrow - for the Heated Oxygen Sensor (HO2S) (G39) and Oxygen Sensor (O2S) heater (Z19) and free up the wire.






- Remove the accessible nuts - arrows - for the front exhaust pipe/turbocharger from above.






AWD:






- Mark position of flexible disc to bevel box flange for reinstallation.

- Remove the driveshaft flexible disc bolts - arrows - from the bevel box while counter holding at the triangular flange with a lever.








The shaft seal - arrow - in the driveshaft flange could be damaged.

• Press driveshaft horizontally as far back and to right side of vehicle as possible.

All Vehicles:






- Remove the nuts - 1 and 2 - on the bracket for the oxygen sensor electrical connector under the underbody. Remove the cover.

- Remove the bolt - 3 - and free up the electrical wire to the oxygen sensor.

- Remove the connector coupling - arrow - from the bracket.






- Disconnect the electrical connector to the Oxygen Sensor (O2S) after Three Way Catalytic Converter (TWC) (G130).

- Remove the remaining nuts - arrows - for the front exhaust pipe/turbocharger from below.






- Remove exhaust system bracket and cross brace - arrows -.






Risk of damaging decoupling elements.

• Do not bend decoupling elements in the front exhaust pipe more than 10°.

- Disconnect the exhaust system at the clamping sleeve - arrows -.






- Remove the front exhaust pipe with the catalytic converter and front muffler.

Installing

Installation is carried out in the reverse order while noting the following:

• For the correct tightening specifications, refer to => [ Muffler Overview ] Muffler Overview.

• Replace gaskets and self-locking nuts.

- Install driveshaft.

- Install exhaust system free of stress, refer to => [ Exhaust System, Aligning ] Service and Repair.











Edition 6 29 2011