I'll continue to update my own thread til I figure this out I guess. Put in the new battery Friday, just went to the stealer and bought an oem replacement to play it safe. After putting the battery in the car starts stronger than ever. First crank after the key turns it fires right up but then starts idling like **** and misfiring on cylinder one still. I drove around the parking lot and the car feels more responsive but still no where near remedied. I guess my next move will be to replace the injector for cylinder one and see what happens. I've also thought about running some injector cleaner through beforehand to see if that helps at all. I've searched and am running out of other ideas unless its a faulty wire or something of that nature. Some help would be great and much appreciated guys. Thanks

 

I have similar problems with a 2004 S4 and the engine started misfiring. This was at low idle. Settled down when put into neutral. Checked codes today and 16691 and 16684 came up. Any ideas? I will try to tighten the gas cap and add a higher octane to see if the problem corrects itself.

 

Hi ben did you get your car sorted ??

 

Mate

Audi Audi Just keeps you guessing !!! their problems

Your misfire problem could be several problems,but i would have told non of what you changed would have been the likely problem
You have a mechanical issue START BY LOOKING
(1) Low Pressure Fuel Pump in the Tank
(2) Suction Tube form reserve Tank main tank
(3) Fuel Rail Pressure Regulator
(4) High pressure fuel Pump

You May also Audi VAG tool for further diagnostician

Let Me know ow you get on