11 78 545 Removing and Installing/Replacing Monitor Sensor

11 78 545 Replacing both oxygen monitoring sensors (N55)





Special tools required:
^ 11 7 030
^ 11 9 150





Warning!
Scalding hazard!
Work should only be carried out on an exhaust system that has cooled down.

Necessary preliminary work:
^ Remove underbody protection.
^ Remove exhaust system.








Installation:
The threads of new oxygen monitor sensors are already coated with Never-Seez(R) Compound (refer to BMW Parts Service).

If a lambda monitor sensor is to be reused, apply a thin and even coating of Never-Seez(R) Compound to the thread only.

The part of the oxygen monitoring sensor which projects into the exhaust system branch (sensor ceramics) must not be cleaned and not coated with lubricant.





Disconnect plug connection on oxygen control sensor (1).

Installation:
Cable color of oxygen control sensor = black.

Cable color of oxygen monitoring sensor = grey.





Release oxygen control sensor (1) with special tools 11 7 030 and 11 9 150 with a suitable extension (2).

Tightening torque 11 78 1AZ.

Important!
When using special tool 11 7 030 in conjunction with special tool 11 9 150, it is essential to reduce the prescribed tightening torque by 3 Nm.





Reassemble the vehicle.

Check function of DME.