Hi guys. I have a 2K A6 4.2 which i get intermittent check engine light issues with. the car runs fine. the codes it spits out indicates that the car is running too lean. when diagnosed by the dealer, they couldn't find anything, or any sensor, to be defective. all of the vacuum hoses seem to be fine as well. they think it could be that the MAF is a little sketchy, but they couldn't give me a definitive answer. it sounds logical, but i don't want to start replacing sensors just for fun since it could get quite expensive. does anyone know where i can get a new MAF sensor relatively cheap? the other alternative they gave me was to ignore the light since nothing is "wrong". THAT IS ANNOYING!

Thanks in advance if anyone can help.

 

Pull of the front cover on the engine. Underneeth are two diaphrams that control the intake manifold changover. Make sure they both suck down. The diaphrams tend to break and leak vacuum. If that seems to check out and there are no other vacuum leaks, you probably need a maf.