just bought 30 days ago a 2010 S5, auto,75k miles,had a misfire at about 3500-4000 rpm and above, codes were P0300, 0306 and 0308. Back to dealer (Chev) who took it to a good foreign car shop, and they replaced left hand Coils and plugs. misfire was at first less, but is back stronger. Codes are P0300, 0303 (occasionally), 0306, and 0308. Dealer is refusing to honor warranty, but that's my problem. Told them that once I find the problem, I will be back if I find it was a warranty issue.
If I accelerate at full throttle, it will completely break down at above 4k rpm, and the CEL will blink and then go to solid light after I back off.
#6 and #8 cylinder misfire remains even after replacement of coils and plugs.
seems like possibles are: cats restricted, carbon in intake manifold and valves, fuel insufficiency (or maybe too much fuel at full throttle). But the cylinder misfire codes are the only ones that I get, no others. ????
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shotts
03-12-2016 12:47 AM - permalinkshotts

 

New Audi S5 owner, with misfire problem, which seems to be a common problem....However, I have researched many sites and asked about this on Audi Forums, with no clear answers.

I see many owners complaining about a misfire problem at 4k, but no answers, except for people giving many opinions, but no answers.

This seems to be so common, that there must be a reason for this problem, can anyone respond on that?

 

Well, it seems that, particularly the S5 forum, is only for people trying to sell us stuff. all well and good, but that doesn't help those of us who have some questions. In the past, I was on Cadillac forums with my STS, and also the Corvette forums with my 99 ragtop, and both of them had quite a bit of interest and feedback from the owners. So, I think I will stop checking the Audi forums quite as much. Good luck to all of you.