Rusky04

I have a 99 audi a8, it trew multiple codes while driving on the highway. Last week the check engine light came on, i took it in for diagnostic check , came out to be gas cap being loose, today the check engine light started to blink and felt like it was misfireing, took it in for diagnostic scan and got these codes ( P0441 , P1250, P1198, P1199, P0455, P0300 ) im stuck right now in diff state in a hotel, my mechanic is about 700 miles away, if someone could help me out by pointing me in a derection to resolve it i would really apreciate it, thnx in advance....

Rusky04

Just disconected coilpacks 1-4 and it seems like that whole side is dead

silverd2

Those codes are all over the map and "seemingly" unrelated, except that you say that all are at the same time or at least very recent...fuel level, evap system, downstream 02 sensors, leak in evap system. A large vacuum leak should trip a lean fuel condition code...downstream 02 sensors only double check 1st set, but have nothing to do with fuel mixture.

One question: Was car exposed to heavy rain or a carwash before this happened? Water in the ECM box, under the hood on passengers side of fresh air plenum.

The "random multiple misfires" (P0300) is the disabling code that making the CEL flash...most common cause of that alone in a 32V engine is Power Output Stage Module...usually starts on one bank of cylinders and can be tested by switching plugs on modules, left for right to see if misfires switch from one side to the other...BUT your code doesn't say (yet) on cylinders on one bank, but still could be problem with POS Module.

silverd2

P.S. There are 2 POS modules (and plugs)..one for each bank of cylinders, mounted on that same bracket in illustration.

My car is a 40V, with different set up...so just going by manual.

Rusky04

just replaced one of the modules and still didnt fix anything, tested every coil pack and everyone of them work.

silverd2

Did you switch one for the other yet?
If so and no change, have you pulled the lid of the electronics box (plenum) to check for moisture or bad connections (corrosion from past moisture) at the ECM. If the the rain drain has ever been badly clogged with leaves (common), it's possible to over flow into ECM box.
Just a couple of guesses, without being there, clearing and rechecking codes.

Rusky04

swapped the modules, no difference, opened the box up, completely clean, spotless and dry,

silverd2

About the only thing left to check with ignition would be signal from ECU to output stages...I've never done that...requires a Vag or other test diode.

If it's not an ignition problem, the misfire code can also be associated with fuel delivery. Bentley mentions injectors, fuel level (a code you had), etc...don't know if all this could be associated with a failing fuel pump or fuel level sensor...sorry, no experience with these specific codes/symptoms.

Might involve checking fuel pressure at the rails, etc..

Maybe more than one could do without a manual and test equipment...and being there.

Rusky04

had compression test done, 6 of 8 cylinders are 170 and 1 is mid 50s and other mid 70s, the guy that helped me out said my timing could be off, is that possibility?

audinutt

most definitely if you compression is that low I would plan on just doing a full timing belt job, first have the engine turned to TDC and verify the cams ARE at TDC. The belt job on a 32v is a PITA and requires special tools.

Sorry about your luck.

-Richard