Audi s4 b7 2005.5 rough idle slightly after coming to a stop

[mnthny4]

Hey to all audi guru's and tech's anybody know how to or have solved a rough idle after coing to a stop ,note very slight rough idle no check engine lights ,misfires readings are ok ,could this be fuel pump related or aftermarket fuel filter related ,fuel filter been the 2port in and 2port out type ,or could it be wiring ,ecm issue ,throttle body issue ,please help all response welcome. UPDATE INFO ,I HAVE REPLACED PLUGS ,FUEL FILTER [NOT OEM TYPE] ,MASS AIR FLOW SENSOR [MAF] ,SWAP OUT COILS ,PCV VALVE AND CHECK VALVE ,VALVE COVER GASKETS PLUS SO MUCH MORE ,SO MY ONLY OTHER THING TO CHECK IS MY FUEL FLOW AND VOLUME RATE AT IDLE ,AND THATS WHERE I NEED THAT INFO FOR THE 4.2L V8,SO ANY AUDI TECHS OUT THERE WITH THAT INFO I WOULD SURE APPRECIATE THAT INFO .further update just check my fuel filter and it is the wrong filter bought from eBay for cheap and did not come with the fuel pressure regulator built into it I checked part number at dealer so I ordered original filter ,when installed I'll update on cars performance after install .so i feel with this the fuel is leaking down from the rail when at idle causing the rough idle ,I hope this solve my issue tho .UPDATE FIX ,so today I went to my dealership and pickup and install my Audi original fuel filter with fuel pressure regulator built into it ,and upon startup I know my issue was solved ,it idle so smooth ,I took it for a road test drive and I was smiling all the way ,so my idle when stop is gone ,I guess the first filter that a got on the car when I bought it was bad and then I got a eBay filter which just confused the hell out of me thinking it was engine related idle issue but just replacing with factory filter making sure part number was correct solved my problem so hope this help others out there ,good luck.

[scorpioS4]

mine is also doing this. pretty sure its the full filler for my car since there is a short whining noise coming from that area when I go to start the car sometimes.

[badger.]

Hey to all audi guru's and tech's anybody know how to or have solved a rough idle after coing to a stop ,note very slight rough idle no check engine lights ,misfires readings are ok ,could this be fuel pump related or aftermarket fuel filter related ,fuel filter been the 2port in and 2port out type ,or could it be wiring ,ecm issue ,throttle body issue ,please help all response welcome.

My best candidates for a rough idle when stopped would be: old/fouled spark plugs, or vacuum leak.
I had this issue a while back, no CELs or anything, but idle would stumble at stoplights and such. Got progressively worse until I changed the spark plugs, then everything was golden again.
Could also be MAF sensor, throttle body, shitty fuel, etc... many possibilities. But I would check the first two I mentioned before anything else.

mine is also doing this. pretty sure its the full filler for my car since there is a short whining noise coming from that area when I go to start the car sometimes.

If there is whining near rear passenger door then it is likely the fuel filter.

[924Carrera]

I still have this fun issue on mine. It's very intermittent and the only indication of the rough idle is that the car shakes. No misfires, new plugs, plus a whole boatload of other new parts. Tonight, I'm pulling the fuel rail and replacing 2 injectors (broken electrical connector tabs, awesome), all the lower O-rings, and all the pintle caps. I didn't pay any attention to the caps and O-rings when I pulled the rail last time to do the intake, and that seems to be when the problem started, so I'm hopeful I will find a small vacuum leak from that area.

[mnthny4]

Thanks for all the help so far ,my car has new maf ,plugs ,fuel filter [not factory oem] ,tried 8 new coils still did the same thing ,the only thing i need to do is to check my fuel preesure at idle flow rate and what it should be ,thats the info i would love to get flow and volume rate at idle so i can know if thats where my issue is at ,so if anybody have info on that for our 4.2l engine i would sure appreciate that help ,thanks

[mnthny4]

Updated original post above with fix ,note that your fuel filter has a fuel pressure regulator built into it and that section of filter can and will go bad over use ,but it's but from my mistake to buy the original filter from your local Audi dealer or if u buy online make sure to get the correct part number match filter for your vehicle vin ,thanks for all input from everybody cool .