11 78 545 Replacing both lambda oxygen monitoring sensors (N52K)

Work should only be carried out on an exhaust system that has cooled down.

Necessary preliminary tasks: 

• 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 system branch (sensor ceramics) must not  be cleaned and not  coated with lubricant.

Disconnect plug connection on lambda monitoring sensor (1).

Release lambda monitoring sensor (1) on exhaust manifold of cylinder nos. 1 to 3 with special tool 11 9 150 (extension).

Tightening torque: see 1AZ in 11 78 EXHAUST GAS CONTROL, LAMBDA CONTROL SENSOR / LAMBDA MONITOR SENSOR .

Installation note: 

Cable color of lambda monitoring sensor (1), cylinders nos. 1 to 3 = black.

Fig 1: Removing Lambda Monitoring Sensor Plug Connection Using Special Tool (11 9 150)

Courtesy of BMW OF NORTH AMERICA, INC.

Disconnect plug connection on lambda monitoring sensor (1).

Release lambda monitoring sensor (1) on exhaust manifold of cylinder nos. 4 to 6 with special tool 11 9 150 (extension).

Tightening torque: see 1AZ in 11 78 EXHAUST GAS CONTROL, LAMBDA CONTROL SENSOR / LAMBDA MONITOR SENSOR .

Installation note: 

Cable color of lambda monitoring sensor (1), cylinders nos. 4 to 6 = grey.

Fig 2: Removing Lambda Monitoring Sensor Plug Connection Using Special Tool (11 9 150)

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.

Check function of DME.