MAF readings?

[Les 51]

Hi Guys,
Need some help please. I plugged my A4 into VAGCOM today to check out some info I was told by the garage that serviced my car.
It came back with no faults (thank god!), but the MAF readings were changing wildly between 130mg/str to 320 mg/str.
Is this ok ? the Specified readings are supposed to be 170mg/str to 180mg/str.
I assuming the MAF sensor has gone wrong and needs to be replaced, but not being very knowledgable about cars I'm not sure .
Any help gratefully received
Thanks

Les

 

[icenutter]

What you need to to is log actual and specified MAF for a full throttle run in 3rd gear. Then plot a graph of mg/str vs. rpm. The rule of thumb is 0.8*mg=power. If actual and specified are wildly different, and/or max values are low then the MAF sensor is probably gone.

My actual and specified MAF values were 5% out and a change of sensor made a small but appreciable difference.

While you are doing this you might as well log and plot actual and specified MAP (mass inlet pressure).

 

[Elberoth]

When your MAF is gonna say good bye, you can see that in the Block 032. Both values should be close to 0. Out of spec values, like + or - 15% may indicate faulty MAF.