maf sensor problem

[zahid123]

i have found on my audi a4 51plate 1.9tdi that the maf sensor is faulty sometimes when i drive up hill it doesnt have the full turbo power and also when the car is fully loaded, my question to anyone is by changing the maf sensor will this increase my mpg?

thanx.

[istoo]

if you are sure its the MAF, try cleaning it first with some carb cleaner and VERY carefully clean the element. May help, if not new MAF.
Typically it will feel like its low on power and poor mpg are all signs. but to my knowledge the diagnostics do not pick this up.
It is very well documented and a quick google shoudl answer all your woes!

[zahid123]

hi mate and tanx for the kwk reply i have read alot on the maf sensor now and alot people say just change it because it is very easly damaged if you try cleaning it, plus is it the blak little box i am looking at isnt it? and how do you clean it do you open it? sori if it sounds stupid

[Davi]

It could improve the MPG - mine has certainly improved since I changed it (the biggest clue to this being I no longer have thick grey exhaust emissions that smell like neat petrol )

Might as well give it a try cleaning it - if you're going to change it anyway it doesn't really matter if you damage the old one! Piece of piss to change too. Cleaning made no difference to mine whatsoever.

Edited by Davi on Tuesday 6th January 11:06

[zahid123]

do i take the blak box of and how? and what do i find inside the box?

[Davi]

fitment varies slightly dependant on model / engine and what you take off depends on where you buy the replacement from - you can either unscrew it from the housing and slide it straight out, or take the entire plastic housing off. If you are going to try cleaning it just take the sensor out the housing, just a couple of torx head screws (actually maybe torx security head, can't remember which) if you are buying a replacement from Audi they will want the old unit in exchange (complete with housing).

[istoo]

the MAF, sits between the Air Box, (big black box) and the Throttle body (the entry to the engine block. Its cylindrical and about 3inches in diameter and about the same in length. Yes they are very sensitive which is why i suggested to CAREFULLY clean. cotton bud or lint free cloth. Sometimes they develop a layer of grime over the sensor disrupting the reading. if you are savvy with a multimeter you can take readings to see if its functioning within tolerance levels. However, as this takes time almost every garage will just replace it and see, but if its not the problem most places will not take them back, given their sensitivity.

an A4 51 plate 1.9tdi, what mileage, these tend to get problematic from 80k upwards.

Removal is fairly straight forward, they will have a cable clipped to one side, mine are held on with jubilee style clips, remove the hoses either side. Not sure on the B6 cars, but you can test a B4 by removing the MAF and running the car to see if it adapts and runs smoother. Someone will correct me if thats not the case with the B6's i am sure.

[zahid123]

will give it a go this weekend thanks for all the advise.