Sometimes we receive a feedback from our clients, that the engine does not accept the new air flow meter.
The first reaction often is to believe that the new part has arrived broken.

But the good news is: In most cases the new air flow meter is not broken. It is very rare, that a new air flow meter from Bosch or LÖWE automobil are broken, since it is part fo the production process to check each and every part.

Therefore we would like to give some advise on what to do, when the new MAF does not work.

Preparation before the installation of the new MAF

1. Make sure that you have ordered and received the correct item

Please read the number on the old part and compare it with the OE-numbers in the sellers’ description.
Usually the description says: OE-number, Originalnumber, reference number or similar.

Here in this examples, the number on your old MAF should be 5WK9600 (VDO-number) or 136203650 (BMW) or 1703275 (BMW) or 8ET009142-061 (Hella).

If you are not sure, if the part fits your car, double check with your supplier.

Originalnumbers 5WK9600Z

2. Replace the air filter and clean the air filter housing

Soot, fine dust, pollen and much more can get into the engine with the intake air while driving.

Electronic components such as the hot film sensor located between the intake and combustion chamber can also be damaged and even destroyed by inadequate filtration.

A new air filter protect against these dangers. Regular filter replacement is therefore absolutely essential. A cheap investment, that will guarantee a longer life of your MAF.

It is also recommended to clean the air filter housing properly with a vaccum cleaner.

Vaccum cleaner
Ferrari Motor

Further steps after the installation of the MAF.

3. Should I reset the ECU?

After changing the defective part, the control unit “learns” the correct data again through the self-adaptation. This learning process may take a long time under certain circumstances – during this time the engine runs “unevenly” and gives the impression that the new air flow meter could also be defective. The engine should then run at idle for about 20 minutes.

If this does not help, you can also disconnect the battery for about 10 min. 

Once again briefly summarized:

Before Installation of the new MAF:
1. Compare the OE-number of the old MAF with the reference numbers of the supplier for this part.
2. Replace the air filter and vacuum clean the air filter housing
3. Clean also the air hose to make sure there is no dirt or oil in the air hose.
4. Make sure that the connector is clean and shows no sign of corrosion.

After Installation of the new MAF:
Usually the motor recognizes the new part and everything is ok.
1. But if the motor continues to have problems, run the engine idle for 20-30 minutes.
2. You can reset the ECU by disconnecting the battery for 10 min.
3. Please take into consideration that other parts can cause similar symptoms and it might not have been (only) the air flow sensor that was broken.