S4 V8 mis-fire problem, need help!
I was trying to find some information on a mis-fire problem I'm having on my recently purchased 2004 S4 with the V8. The car has only 13,000 miles on it, but this problem has gotten very bad all of a sudden. You can feel it misfire driving but it doesn't always throw a light. I barely made it home this weekend from SC to OH. Sometimes the light blinks and if I kept going it would go off right away but other times it would stay lit. I would pull over once lit and clear the codes. And it would sometimes be fine for awhile and others come right back till I repeated this step. Previous owners records show he had complained of this at around 12k @ dealer but dealer reported no problems (when I first got it, it was much more spuratic now I can't hardly drive it. Codes are always : 16689 P0305 Cyl 5 misfire, 16684 P0300 Radom misfire and 16589 P0205 Cyl 5 injector circut N83 Open. Prior to my trip I had the plug and coil pack for # 5 replaced and the injector from 5 switched to 6, but the codes stayed the same (still alawys 5)? Was there ever a know problem that could cause this? Any help would be appreciated as I love this car, but am very frustated at the moment and local dealer does not have a very good rep. Would you know anyone near Dayton OH that is very good ( a long shot, but thought I would ask)? Idle is always smooth at start up so far. I read about a bad Ignition Control Module on a 4cyl causing similar problems (always just one cyl) , does the s4 have one of these as well? If so were would it be located? Thanks in advance for any help.