BMW 11787545074 O2 Oxygen Sensor

Oxygen sensors are installed at the front and rear of the catalytic converters. Prior to sensor removal, use a BMW scan tool or equivalent to read out and clear ECM fault codes. Care should be taken when handling oxygen sensors, as they are easily damaged by shock. To avoid possible engine damage, do not mix up oxygen sensor connectors; mark connectors before disassembling. Begin by removing the upper engine cover, raising the vehicle, and supporting it safely. Disconnect the oxygen sensor harness connectors. For pre-catalyst oxygen sensors, release the right side tie rod from the steering rack. The harness connector for cylinders 1 - 3 is colored black, while the connector for cylinders 4 - 6 is colored grey. Installation is the reverse of removal, ensuring to apply a small amount of anti-seize compound to sensor threads and confirming that the sensor electrical harness connectors are routed and connected correctly. Avoid overusing anti-seize lubricant and do not contaminate the tip of the sensor with it. When using tool 11 7 030 together with swivel tool 11 9 150, reduce tightening torque by 3 Nm to 47 Nm (35 ft-lb). For post-catalyst oxygen sensors, the harness connector for cylinders 1 - 3 is also colored black, while the connector for cylinders 4 - 6 is grey. The same installation precautions apply, including the use of anti-seize compound and proper routing of connectors.