Catalytic Converter: Service and Repair

Catalytic Converter, Removing And Installing

Removing







- Remove bolts (arrows) and remove engine covers -A- through -C-.







- Remove air distributor (arrows).

For right catalytic converter







- Disconnect connector -1- for oxygen sensor before catalytic converter at bulkhead.
- Disconnect harness connector of oxygen sensor behind catalytic converter from cylinder bank 1 (component location).

For left catalytic converter







- Disconnect connector -2- for oxygen sensor before catalytic converter at bulkhead.
- Disconnect harness connector of oxygen sensor behind catalytic converter from cylinder bank 2 (component location).
- Lower transmission
- Manual transmission.
- Automatic transmission.







- Remove shielding plate -2- from turbocharger.
- Remove upper bolt -3- from front line to turbocharger.







- Remove heat shield (arrows) above drive axle from transmission.
- Unbolt drive axle -1- at transmission and tie it up.







- Remove transverse beam (arrows).







- Remove strap (arrow).







- Remove transmission support (arrows).
- Loosen exhaust system clamping sleeve and slide it to muffler.







- Remove hose clamp -1- from shielding plate for turbocharger.
- Unbolt exhaust pipe -2- from turbocharger.

NOTE: Do not over-bend flex pipe of decoupling element (flexible pipe connection) at front exhaust pipe. Catalytic converter may be bent only a maximum of 10 degree to front line, otherwise the decoupling element will be damaged.

Installing
- Installation is performed in the reverse order of removal.

NOTE:
- Cable of oxygen sensor must always be secured in the same position when installing so that contact with the exhaust pipe is avoided.
- Coat oxygen sensor threads with hot bolt paste. This paste must not contact sensor openings.
- Hot bolt paste
- After loosening bolts, double clamp must be replaced.

- Adjust the pre-tension of center muffler to catalytic converter.

Tightening torques
Threaded connection Tightening torques
Exhaust pipe with catalytic converter to
turbocharger 30 Nm
Shielding plate to turbocharger 10 Nm
Clamp for exhaust pipe 40 Nm
Heat shields above drive axles to transmission 25 Nm
Drive axle to transmission 70 Nm
Beam to underbody 20 Nm