I got the same code and replaced MAF sensor but still got the code. Also had a very slight vacuum leak, which was giving the P0171 code because it was forcing the short term fuel trim to compensate for the slight vacuum leak. It turned out to be the purge valve that was causing the P0171 code. And the purge valve is actually cheaper than the MAF center, and almost as easy to replace. Never occurred to me because last time my purge valve went bad, the big symptom was every time I got gas it would take me 10 attempts to get the car started. Which if you have that issue, you can simply clamp the line shut and if it starts right up you know it’s bad. And as most of us that own the A4 B7, at some point your car burns about a quart of oil per month, it may be your oil separator (aka crankcase vent valve - again very expensive about $45 and easy to replace) if you try the easy test of trying to take off your oil filler cap while the engine is idling (if it’s difficult your crankcase vent valve is what’s bad) but if it’s easy, we can still be replaced and that will solve losing the quart per month. There’s a lot that I can tell you it’s your down stream O2 sensor or your catalytic converter is bad, but if you have or get an OBD II scanner, even a $25 one like Launch Creader 3001, live datastream works sufficiently. Of course if you want much more detailed and customization you need to get a better one.

@ronaldrrootiii6040

3 ай бұрын

Just curious do you have info on what numbers should be on live data? Like what are the average numbers throughout all the information on live data? Because I see a lot going on on the screen but don't necessarily know what good numbers would be as far as the live readings of everything. Or do you have a link that tells me every single thing on there what its average should be and what it should be

Fpc euro online can get that maf sensor for about 34$ and o2 sensors for about 50$ each

Hi, my 2007 audi a4 b7 has very weak rev at idle. I stepped on the gas and the rpm just slowly goes up. Before it revs up nice and strong. This just happened after i cleaned the maf. I got no error code. Any help would be greatly appreciated. Thanks

@user-dk3ph8oe3b

8 ай бұрын

Give the maf time to dry itself fully. After cleaning if u put back in wet car won't start. Let it run and give it a few days and clear the code

Those screws are a T what?

@ronaldrrootiii6040

3 ай бұрын

I think t20 or 25 torx