Genuine OEM Audi Air Mass Meter, part number 038906461B. This sensor is a critical component of the engine management system, precisely measuring the mass of air entering the engine's intake. This data is essential for the engine control unit to calculate the correct fuel injection quantity and ignition timing. It is typically located in the air intake tract after the air filter. Weighing approximately 0.28 kg, this sensor provides accurate readings. Using a genuine OEM air mass meter ensures factory calibration and signal accuracy, which is vital for maintaining engine efficiency, power, and emissions compliance.