Oxygen Sensor: Service and Repair

Oxygen Sensor

Special tools, testers and auxiliary items required

• Box wrench set (3337)

• Hot bolt paste G 052 112 A3

Work sequence

- Disconnect connector for oxygen sensor and move wiring clear.





2 (brown) to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130)
5 (black) to Heated Oxygen Sensor (HO2S) (G39)

• To gain access to the connector, remove coolant expansion tank bolt (arrow) and move expansion tank to side. Fuel hoses remain connected.





- Remove oxygen sensor using special tool (3337).

When installing, note the following points:

• The screw thread on the oxygen sensor is coated with assembly paste. This paste must not be allowed to penetrate the openings on the sensor.

• Tightening torque 55 Nm.

• When installing, the oxygen sensor wire must be secured in exactly the same position as before in order to avoid contact between the wire and the exhaust pipe.