hi i have a 200 s4 with 80k on the clock.
my check engine light came on
i pulled the codes and they were p0300 thru p0303 cyl misfire 1 thru 3
i replaced all 6 plugs all 6 coils all 6 plug boots. as well as the ignition control units. i swaped cam sensors side to side. checked if for vac leaks with carb cleaner.
i still have the same misfires. i am stumped.
i have a pretty advanced scan tool and i can monitor the misfires. it seems to only miss at idle.
my missseems to be very minor.the car runs great and doesnt shutter of stumble.
any healp would be great thanks

 

possibly an air Leak through the injection for # cylinder

 

i checked for vac leaks with carb cleaner. and i also used a smoke machine to smoke the intake mani. i didnt see any evidence of a leak. if there is one it is very verysmall. i am going to pressure test the inake and see if it holds pressure

 

You said you did replace ur ignition control modules? Thats what happened to mine. Except it was only missfireing on cyclinder one. So I swapped the plugs on the ICM's (since we have 2) and it was misfiring on the other side. But i see you say that u have done the ignition control units. Same thing i guess.

 

yeah i had the same problem you had, i just reset mine after i replaced the icu and plugs. I still get the missfire from time to time but cause it is not a bad misfire it does not go into slug mode. Still have not figured out what it is just comes and goes every other month for a day for so. Plus i dont want to pay audi to look at my car F'ing 350 just to look at it.

 

todayi did a compression test on cyl 1 2 and 3 and i have 160 to 170 lbs i swaped some coils sided to side even though there all brand new.
i am really lost. most of my misfires are coming from #1 and #2

i pressureized the intake and added smoke, i found one small veryvac leak, fix it but that wasnt the problem.

 

I got Misfire too from p0300, p0303 and p03004
anyone tell me do i need to spend some money to fix it or just leave it there which is not a bid deal?

 

Did you try O2 sensors? even your MAF?

 

MAF! ...50 bucks says it's the maf sensor causing all your problems... good luck!

 

well i figured it out. my cam to cam gear timing was off. causing the whole bank to miss.