hey hows it going everybody,
new to the forum and new to audis..
i Bought my 2000 a6 with the 2.7t and 6speed manual trans (180k miles) a couple weeks back. paid 1500 for it knowing it needs some work. always wanted an audi and thought it was too good of a deal to pass up. the only problem the previous owner told me about was the driver side cv axle which i put in... noticed the vehicle speed sensor took a beating when the axle went and ive got that on order. took the audi to work yesterday which is 35 miles away. halfway there as i was driving (around 55) it fell on its face...the accelerator wasnt responding for a few seconds then it came back.. this happened a couple of times before i got to work..hooked up the scanner and got the following codes:

P1177- 02S correction behind catalyst, b2 limit attained
P0501- vehicle speed sensor a range/performance
P0507- idle air control system rpm higher than expected
P1121- H02S 2 bank 2 heater short to ground
P1140- HO2S 2 Bank 2 Heater Resistance Too High
P0158- 02 circuit high voltage (bank 2, sensor 2)
P0150- 02 circuit (bank 2, sensor 1)

took the car out for a spin at lunch and it seemed alright.. on my way home, the hesitation came back. then it got worse and was more of a sputter, and the same time the check engine light was flashing. completely lost power and was barely limping along. i pulled over and at idle it stalled. tried to start it and it would just keep cranking, wouldnt fire back up. its home now still unable to start with the same codes. havent got a chance to look into it more but im just looking here for some ideas and help.. thought it may be coil packs or plugs but theres no codes for misfires or anything with ignition..maybe fuel pump? hopefully something small and simple..any help would be greatly appreciated..
thanks, and sorry for the long post

 

Standard reply...look for vacuum leak(s).

 

okay..ill start there, thanks

 

might be fuel filter.....

 

it has a new fuel filter..i should have also mentioned that the EPC light came on

 

EPC stands for electronic power control. The ESP (Electronic Stability Program) if so equipped utilizes the brakes and the EPC to control oversteer/understeer within the limits of physics.

IF your EPC light comes on and you have poor performance something is triggering the EPC and reducing power.

Could be a MAF or MAP sensor or the drive/by/wire throttle body but your scans don't show that.
Get the speed sensor fixed and your 02 sensors.

 

went to replace the vss and cant find the connector that goes into it or any wires...must have gotten ripped out from the axle. where can i get a wire diagram?
i wonder if because the car thought it was going so fast all the time with the speedo going haywire, something really got messed up? ive read online and in the owners manual about the electronic speed limiter and how the ecu will shut off the injectors at high speed until you slow down...that sounds like what was happening and now maybe its stuck like that?? or maybe im over thinking this?
i just want to fix the car and
drive this baby!

 

forgot to update this problem....last week i got it to my friends shop who has a lift that made working on the car so much easier....found the connector to the vss got that in. the fuel gauge was pretty low so i thought maybe i ran it too low and got some bad gas at the bottom of the tank replaced the fuel filter and it still didnt start... threw in 5 gallons of fresh gas and she started right up and ran awesome. thought i was just a dumbass and let it run out of gas. i filled it up and the fuel gauge only went to the 3/4 mark so now i know somethings wrong with the gauge. the driver info display has been messed up since i bought it, its scrambled and you cant make out the words on the screen. maybe the cluster itself is bad? last week end it was running awesome so i decided to drive it to work monday, no problems... ran great until yesterday when i reached the 1/4 tank mark the problem came back like it was misfiring, the cel was flashing...luckily i was almost home and made it to my driveway...hooked up the scanner and this time i got a code for a random misfire. i live near a shell gas station so i drove it there and filled it up again..now its running great again! i read on this forum about these gas tanks having 3 different level sensors? maybe the bottom one is bad? have never ran into this problem with any car or truck

 

There was a batch of cars with fuel sender problems that were apparently caused by North American gas (don't even ask about Mexican gas) sulphur...Audi replaced the sender on our 2K4.2A6. Fuel sender might be part of the fuel pump in the tank..accessed under the rear seat.

if you can't get a full/empty reading by shorting the fuel sender terminal to ground, replace the fuel tank sender. If you have a couple hundred thousand miles on the car you could also consider replacing the fuel pump.

 

Sounds like the fuel problem is that the gas gauge is misreading. Do you have any idea how many miles you got from the "full" tank of gas? I ask because the gauge could be off and you actually ran the tank dry (should get around 400 miles to a tank) or the fuel pump pickup could be messed up and the pump sees air before the tank is really empty. In either case, the lack of fuel will get you the exact symptoms you are seeing, and all the codes show up because the ecu goes crazy trying to run an engine with no gas.
Either way, it sounds like there's a problem in the gas tank. Good news is that you can get to most of the parts through access points under the rear seats. Figuring out exactly what's wrong will take getting into the fuel tank, so be careful working there - fumes and fire hazard, obviously.

The display pixel problem is extremely common. Solder connections in the instrument cluster actually break and give you the messed up display. Unless there's some other problem with the cluster, I wouldn't replace it - too much stuff to re-program if you do that. I have had mine repaired by these folks - http://www.ebay.com/itm/290621013927 $155 total and one day turnaround once they received the cluster. Just take it out (several posts in this forum on how to do that) pack it really well and send it off. They did a beautiful job, plus they warranty it for a year.
Jim