You have received a new mass airflow sensor for your BMW, Mercedes-Benz or Porsche, installed it and looked forward to a positive driving experience and still:

– The car has power holes.
– The idle speed fluctuates.
– In short, the engine behaves as if it is not getting any air.
– Not to mention that the car is not reaching top speed.

As long as it is an original part from Bosch or VDO or a quality aftermarket part from LÖWE and not a cheap imitation, the complaint rate is extremely low to our experience. The percentage of parts that actually do not function correctly is less than 0.5%.

What can be the reasons for a new MAF to fail?

Often the reason for the problems are not the new MAF, but they can be found elsewhere. There are a whole range of other sources of error:

1. The ECU has not yet recognized the new MAF and is still running with the values of the old part. Please read the following blog post

2. Your technician is not happy that you bought the mass airflow sensor for half the price somewhere else, but would rather sell you his own products.

marten in nature
Quelle: Photo by Zdeněk Macháček on Unsplash

3. Other parts in your vehicle are defective and cause the same symptoms.
For example defective vacuum hoses or defective cable connections to the air flow meter, for example due to marten bite. Yes, these cute little animals obviously do not stop at football fields or engine compartments.

marten bite motor
Marder bite
Idle Air Control for BMW

Other parts that cause the same symptoms are

d) Defective EGR valve

e) Oil film in the pipe to the air flow meter, e.g. due to oil vapours. By the way, this can lead to the new MAF being defective again after a short time.


f) Dirty fuel filter


g) Very often the lambda sensor is also defective and has not been replaced.

h) Idle Air Controls and Throttle Position Sensors are also responsible for the air supply in the vehicle. It might be a good reason to replace them as well.