I recently bought a 2003 Audi A4 1.8T Quattro w/ 50K miles. I thought i got a good deal, until i got the car home and there are multiple problems and i could really use some expert advice (i'm not the best mechanic, esp with Audi). When i first got the car, it idled very rough and the check engine light came on. Took it to an Autozone and multiple fault tests were received. I replaced the plugs, mass air flow and one air hose/valve which had a leak near the back of the engine. This fixed the rough idle problem and i got Autozone to clear the codes but the Engine light came back on. Now there is only 1 fault code, P0171. I've seen some forums saying to check for any leak or possibly the O2 sensors? Anyone know what else or could be more specific? I hate to take it to a garage and pay $$$.

Also, the horn doe not work at all and i can't even find it under the hood. I found a wire that is just hanging underneath the covering on the driver side, maybe this it and the horn is gone?

As if this wasn't enough, the windshield wipers don't work at all either. There is fluid in the tank, but when i try to fill it, it is leaking from somewhere (maybe the line?) b/c the computer doesn't say anything about filling the fluid tank. There is just no power at all when i attempt to clean the windshield.

Any advice would be great. i dont want to be steered away from audi b/c the car handles so well and has plenty of power. Thanks.

 

http://www.obd-codes.com/trouble_cod...gen-sensor.php

have u checked the vacuum hose going into the intake manifold
or do u gave an aftermarket intake filter

 

that is my next step tomorrow after work. i saw a good pic on here showing where that is. i'll keep you updated? any idea about any of the other problems?

 

The P0171 is due to the engine running too lean. This could be a vacuum leak, bad or dirty MAF, or clogged fuel filter.

The horns are located behind the front bumper. These are prone to failing in these cars. Replacing them will solve the problem. Do you hear the horn relay click when you press the horn?

As for the washers, check fuse #37 (fuses are behind a pop-off panel on the driver's side dashboard, the part that is exposed when the door is open). It's marked "Intelligent Power Module", but it powers the washers. The leak (and the blown fuse) is probably due to a faulty pump.

 

Thanks a lot for the advice. I don't remember hearing any relay at all when i push the horn, almost as if it's disconnected completely. I am going to try and work on the car as much as i can tonight and check some of these problems, everything else will have to wait until the weekend but i'll keep you posted. Thanks again.

 

Today I went and checked over everything that i could get to. I didn't see anything out of the ordinary, except there were some loose and misssing hose clamps. I replaced 6 and tightened everything that i thought could be affecting this P0171 code. There was nothing wrong with the connection from manifest so i'm ruling that out. I got the codes cleared and am going to drive it some and see what happens. I guess if it comes back on, i'll look into the fuel filter then possibly the O2 sensors?

Also, the horn is missing. Can't figure that one out, but i'm going to order a new one. Any suggestions where (discounted places)?

Finally, the fuse #37 seems fine, so i'm assuming the problem lies with the pump? I'll probably end up replacing the pump.

Any more help is useful. Thanks.