Mercedes-Benz W202 mass air flow sensor (MAF) – symptoms, cleaning and replacement

Not in all versions. In the 1.8 and 2.0 litre M111 petrol engines the air quantity is estimated from the intake manifold vacuum sensor, the throttle position, the temperature and the engine speed. The 220D does not have the sensor either. The sensor is found, for example, in the C200 Kompressor and the CDI engines.

Typical ones are hesitation when accelerating, lack of power at overtaking speeds, uneven idle and poor starting. The symptoms can also be caused by an intake air leak or other sensors, so check for leaks and, for example, the temperature sensor before replacing it.

A dedicated sensor cleaner (e.g. CRC Air Sensor Clean) can help if the sensor is dirty or oily. If the sensor wire is broken or the electronics are damaged, cleaning helps only briefly or not at all, and the sensor has to be replaced.

Use the original Bosch sensor, as a cheap aftermarket sensor has caused starting difficulties and unstable idle. For example, the Bosch number for the C200 Kompressor is 0 280 217 114. The new sensor does not need to be taught, and the battery does not need to be disconnected.