You don't give any info at all !
Where?
What car model/ age / miles.
Does not seem familiar in all the 8 years of this Giulietta section....

 

Broken or loose wire to the maf sensor. Any decent garage should have been able to check the live data from the maf and see if the readings were plausible. A broken wire would soon show up.

 

Faith should be lost in the diagnostic operative?

 

Sorry first time posting it's a 2012 alfa Romeo gullietta veloce 2.0 jdtm 105,000 on the clock in uk. Well I had 2 auto electrictians look at it and they said it was mass air flow sensor so got that changed twice, but they seem to think it's mechanical fault.

 

If the map is genuinely okay then the airflow through must be way down. (assuming it maf reading low) which implies:

1. a big leak after the maf so air is getting to the the turbo but bypassing the maf,
2. a blockage pre maf,
3. your egr valve is stuck partially open so air is bypassing the engine (instead of exhaust entering the engine, air is revers flowing and entering the exhaust bypassing the engine) (maf would read high if this was the case)
4. turbo vnt mechanism has seized in the high rpm position and low rpm boost is low as would be airflow.

A proper check of the live data: namely mass air flow and boost pressure would shed more light, not just reading the codes.

 

No problem. It could have been a new petrol Giulietta and things could have been different!

 

I understand �� I was thinking maybe it could be something inside the turbo housing? as they only checked the outside of it and not the inside but apparently they have said it's fine. When i had the egr and dpf changed it was because it was full of soot and had caused a back pressure which resulted in the car breaking down and oil getting inside the turbo (limp mode and engine light was already on at this point (maf code)

 

I had similar problem, and after a long time of nervous trials to find the problem and a lot of spent money...it was that wrong MAF sensor was installed. If you use BOSCH, find the one that is for cars WITH start&stop function. Check that out first.

 

Oh really I never thought of that thank you will check that!

 

So it turned out to be the timing belt/pulley the alfa specialist said its very unusual and it was the last thing they checked as the error code was indicateing the maf. So anyway it was replaced and now it drives like a dream �� so happy to have it back on the road. (Thought I would post an update just in case anyone else has had the same issue and needs advice.)

 

How did he found out that it was the timing belt? Was it worn ? How many km's ? How old ? Tnx for the feedback on the post! Because I just got MAF errors on the car.