Genuine OEM Audi Lambda Oxygen Sensor, part number 4M8906265E. This critical sensor measures oxygen levels in the exhaust gas, providing essential data to the engine control unit for fuel mixture adjustments and emissions regulation. It is typically installed in the exhaust system, either before or after the catalytic converter. Weighing approximately 0.139 kg with a cable length of 0.45 m, this sensor is built to exact specifications. Choosing a genuine OEM sensor ensures precise calibration and signal characteristics, which are vital for maintaining engine efficiency and meeting emission standards.