maf fault after air filter change!!

[Buxton2901]

Hi guys. I have recently replaced my air filter for the first time on the A4 and now have a maf fault p0101
When I took the old filter out there was a large rubber o ring which was not supplied with the new filter and I could not get the old o ring to fit the new filter so I fitted without thinking it didn't need it.
Would this cause a vacuum leak and subsequently the maf fault or maybe the maf sensor is bad?
Anyone had the same issue?
Thanks
Paul

 

[desertstorm]

Yes those rubber rings are a right pain to get in, spray mine with WD40 and that makes it easier to fit.
http://wiki.ross-tech.com/wiki/index.php/16485/P0101/000257
The rubber ring won't be an issue. Is the air filter a standard paper filter ?
You could try logging specified and actual MAF values to see how far out the MAF is, they don't last forever unfortunately so could have gone faulty.

 

[Buxton2901]

Thanks for replying Karl.
Yes it's a standard paper filter with the foam cover around it. I'm worried I damaged the sensor when I was man handling it trying to get the filter to fit with the o ring.
Is there a way of cleaning the maf sensor as I've read it may just need cleaning ?

 

[desertstorm]

You can clean them but don't use anything aggressive like brake cleaner or thinners . Something like Iso Propyl alcohol.
http://www.maplin.co.uk/p/servisol-isopropyl-alcohol-200ml-re87u
Could also be a leak in a boost pipe ? , did you secure the intake pipe correctly at the turbo end.

 

[Buxton2901]

I think I did but will take it all off again and try cleaning the sensor.
Do u think acetone will be OK to use?

 

[desertstorm]

I wouldn't use acetone, it's good at dissolving plastic. Many years ago the wife (Blonde) put some fake nails into nail varnish remover (acetone) the next day they had dissolved .

 

[youngy93]

electrial contact cleaner is good aswell, get it at most electrical shops

 

[Buxton2901]

So I've had it all apart again and it looks like the airbox wasn't closed properly.
There is a tab at the bottom which wasn't correctly aligned therefore there was a gap and I assume it wasn't sealed and caused a vacuum leak.
Had bought the electrical contact cleaner anyway so gave the maf sensor a good spray for good measure. Just wait and see if the fault code comes back now but I'm confident it's sorted now.
Cheers guys