Hi guys, I seem to have a problem that just doesnt want to go away. I have a 2000 A4 Avant Quattro 1.8Twith 108,000 miles. Not even Audi can decide what the problem is. The problem first came about when I was on the way to Munich doing about 100 on cruise control, all of the sudden the CEL came on. So, on the way home I stopped at the Audi dealership in the VAG-COM, 2 Faults came up, both Sporadic, one was a ground problem, didnt say where, and the other was Poor Air/Fuel mixture. The computer said that they were sporadic and not current and deleted them. Now, again, autobahn, 20 mins of driving and the light came back. It goes off after about 5 or 6 times after starting the engine. Only thing I have done electrically to the vehile is added a 200 watt amp, wired directly to the battery like it is supposed to be with an inline fuse, I used to install systems at circuit city so I am pretty sure that I set it up correctly. The car is running perfectly and the voltmeter is steady at 14 volts. Any ideas anybody?

 

Can you remember/get the exact fault codes #'s?
I wish I could drive on the Autobahn [:@]

 

Ok, I just got back from my car, the dealership printed out the faults through VAG COM for me, so thank god I still have it. But, i am not sure which is the fault code, so I will write it like I see it on the page,

Fault 1.

18010, P1602

Fault 2.

17536, P1128

So, one of those numbers for each fault is I am sure the fault code. Any info would be awesome!!!

 

P1602 = low voltage to the ECU from the battery ( check the ground connections ) and if the battery is in good charged condition,

P1128 = posible air leak in a vacuum line/AIR system/hose leak

 

Ok well since he cleared the codes, and now again you have the CEL/problems, you need to get the ecu rescanned again for fault codes to see which one(s) came back. The P1602 code (Power Supply (B+) Terminal 30: low Voltage [Sporadic]) can mean your battery ran dead or was disonnected at some time, and the P1128 code usually points to a bad MAF sensor- which is probably the cause of your problems, but can also point to a leaking vac line(s). I dont know if you have autozone over there or a car parts store that can scan for free like we do here, but thats what you need to do. See what fault code(s) came back. The P1602 may had been stored from 3 years ago if the battery went dead or something. But Im really thinking the P1128 code is the problem and probably a bad MAF.

 

Ok, thanks for the excellent assistance. No, unfortunately no Autozone here, but Audi scans the ECU for free. I am pretty sure the P1602 fault came from when I disconnected the battery when installing the amp. But I am definetly concerned about the P1128 fault, being a possible MAF problem. What would a new MAF cost me? Or should I just clean it out? If so, what should I use, buy the way, didnt get that fault till I installed my K&N filter, which I took out of my passat so i wasnt over oiled. Odd.

 

Well Im not calling you a liar, but if it happend right after you put the K&N filter on, it was probably over oiled and fouled up the MAF.Although it could be a badwiring connection at the MAF, maybe the harness isnt seated all the way. You can take the maf out and try to clean it with electronics cleaner or isopropyl /rubbing alcohol. Cleaning it is usually only a temporary fix though, you likely have to replace it eventually. And because its causing a lean condition, the sooner the better. I always recomend www.ecstuning.com for MAFs as they typicaly have the best prices on them, but I dont know if youd want to pay the shipping from the US.

 

If you need to replace the MAF, try to get a remanufactured one.

 

Well, got home last night and let everything cool down. On the way home I bought a new OEM Air Filter and some MAF sensor cleaner from the local parts store here. Took the Airbox apart and removed the MAF. Then I cleaned it with the spray and used compressed air to ensure that it was fully dry, replaced the air filter and also cleaned out the Airbox, its unreal how much **** gets inside there and what gets blocked up at the screen in the inlet. While taking the airbox out i noticed that the line that goes into the secondary air pump, at least thats what I believe it is, its left of the air intake hose that goes to the intercooler, was disconnected, so I reconnected it also. After putting everything back together, I started that car and the CEL went away. I do notice that its running a little better, which may be a result of the cleaning, that MAF was filthy. I also priced a new remanufactured MAF from Bosch here in Germany, they want 120 dollars plus 25 dollar core charge for my old one. So, if the light comes back I will just change it out. Thanks again guys for all of the help.