hi i have 2001.5 s4, no mods except a bi-pipe and dv valves so far, about a weak ago the check engine light came on after i filled up with gas. it started sputtering and i lost power... down to 5 psi max. so i figured it was bad fuel or wrong octane. a couple of tanks and octane booster later its still doing he same thing. ive checked codes cleared and rechecked. all i come up with is multiple misfires in cylinders 2, 3, and 5. ive checked maf icm, coolant tempsensor, vacuum leaks(i kinda hear something at the back of the engine, but i dont think its a leak, i sounds like it coming from the tranny) ive replaced spark plugs and switched coilpacks its still the same, i dont know if there is a way to test the egt sensor or if that would throw its own code. the car idles a little rough, vibrates during acceleration in low rpm... i have to keep the car around 3000 rpm to smooth it out and has no power. any help is appreciated

 

It wasn't showing any signs of problems before the refill?

How soon after the refill did it start to show symptoms?

Can you run codes again and tell us exactly what ones they are?

The low rpm vibration and lack of power are partially because it's running in limp mode.

 

16684
P0300
Random/Multiple Cylinder Misfire Detected

16686
P0302
Cyl.2 Misfire Detected
16687
P0303
Cyl.3 Misfire Detected

16689
P0305
Cyl.5 Misfire Detected
these are the codes ive also hooked it to vag and watched it misfire
it wasnt showing signs before the refill and it happened right after... it took about the amount of time it would take for the new fuel to hit the injectors. thats why i thought it was bad fuel at first

 

anyone?

 

im logging off for the night ill be back on tomarrow

 

I'm having the same problem, sometimes when i floor it, the car sputters and the engine light comes on and off numerous times then goes away... ive changed everything you changed, DenoMckraken in regards to the coilpacks, o2 sensors, fuel filter.... and sparkplugs. What could it be? anyone?

 

well i just ordered a new fuel pressure regulator, it comes in tomarrow, and toninght im going to rip apart the injectors and ohm them out... hopefully its one of the two. i really didnt want to deal with the injectors but i dont think anyone has anymore ideas. ill keep you posted Audi.ro

 

please respond if you can think of anything else that i didnt, i wont respond till tomarrow... maybe late tonight but ill be able to check them on my phone

 

EGT will SOMETIMES throw codes when they go bad. I know mine "sort of" threw intermittent codes, but had been bad for a while before throwing codes.

When you say you checked your ICM(s) -- how did you verify that it wasn't the problem?

 

This one is a little strange.
For some reason, I want to think that the fill-up was coincidental.

The most logical things I can think to check would be the EGTs like meatbiscuit said, Have you tried to run it with the MAF disconnected?
Do you have a boost gauge? If so how many inches of merc. are you showing in neutral at idle?
Lastly, does the car exhibit symptoms in open loop when it is first started or only in closed loop after normal O.T.s are reached.