Hey this is my first post here and hopefully someone can help me out. I have a 2001 s4, a few weeks ago it was throwing a code for a random misfire and misfire on #5, blinking engine light then solid (would only misfire upon wot). Replaced #5 plug; problem gone. Driving today and light came on and car was stumbling no matter how easy on the gas i was. Didnt have a chance to go and get any codes pulled, but replaced the 5 other plugs(assuming it was misfire again). Took it out for a test drive got down the road and it was fine. Light comes on and stumbles through throttle position again, i dont have a boost gauge but there def is very little boost. Any ideas? i'll go to achtuning and get the codes pulled tomorrow. Thanks.

 

You will probably get another No.5 misfire again when you check the codes and my best guess would be a bad coil, they are known to go bad on these cars. You can test it by moving the coil to another cylinder but if you already replaced the plug and it comes back up on No.5 then im sure that its the coil.

 

thanks David. You were right. Went to Achtuning to get codes pulled:

17697
F1289-35-10 N249 BOOST CONTROL VALVE

16684
P0300-35-00 RANDOM/MULTIPLE MISFIRE

16689
P0305-35-00 MISFIRE #5

16686
P0302-35-10 MISFIRE #2


Anybody have had this same thing happen? It was recommended that i move some fuel injectors around and see if problem persists; and change the valve out as well. Would that n249 valve cause misfires?

So far Ive changed all plugs and coil on #5.

Thanks.