11 78 545 Removing and Installing/Replacing Monitor Sensor

11 78 545 Replacing Oxygen Monitoring Sensors (N55)

Special tools required:







WARNING:
Risk of burning.
Work should only be carried out on an exhaust system that has cooled down.







Necessary preliminary work:
- Remove underbody protection.







Installation note:
The threads of new lambda monitoring sensors are already coated with NEVER-SEEZ compound (refer to BMW Parts Department).
If a lambda monitoring sensor is to be reused, apply a thin and even coating of NEVER-SEEZ compound to the thread only.
The part of the lambda monitoring sensor which projects into the exhaust branch (sensor ceramics) must not be cleaned and not coated with lubricant.







Disconnect plug connection on oxygen control sensor (1).

Installation note:
Cable colour of oxygen control sensor = black.
Cable colour 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.