OK, I've been getting this problem for2 weeks now but still no codes. Whenever I step on it hard it starts to sputter and my guess is it's misfiring, this happens on any gear. Also it runs normal when I don't push it. I replaced the ICU in July with a brand new one so I don't think it's that. I've used ignition cleaner on my last 2 tanks nothing changed. I've replace the check valves in october as well as most of my vac lines. No boost leak noticed on the boost/vac guage.

I NEED HELP!!! This one's got me stumped!

 

ignition cleaner ??
stop using that, change your coil packs, and spark plugs

 

If you have access to a Vag-Com, you could check the engine controller for misfire "latent" codes, also, you could log your correction factors when you are doing the pulls and see if you are knocking/detonating.

 

its your coil packs vag the car and see which one is causing the problem

 

I've vaged the car but so far there's been nothing logged, sigh... Going out to see if I can log something on vag.

 

maybe coils. I have also seen cam adjusters do kind of the same thing. does the car tick really bad at idle(like vavles ticking)

 

A miss almost always sets a light. I guess you could check the MAF too

 

Sounds like a vaccume related problem to me.

 

hey, my car is currently doing the same thing however the boost levels arent up to what they are suppsoed to be unless I installed my boost gauge wrong. Anyway, I have been advised by my tuner to replace the coil packs and spark plugs as others have said... and to get my CEL light to come on again I had to just try to just run it a little harder when it misfired, as painful as it is to do. I got misfires in 2 cylinders and a random one but havent been able to figure this one out either...the replaced coil packs did work for a week though!

 

OK, I finally got it to throw a CEL and it was for multi cylinder misfire 16684 and cylinder 2 16686 and 3 16687. Just like limptimtim. Then I cleared it and ran it some more and got missfire detected prob low fuel. But at this point I really was low on fuel and my get gas now light was on. I changed my plugs last winter, do they only last a year? I've got the NGKs.

Also I was logging engine group 014 and 015and was getting lots of hits in the "count" columns when it was doing the sputtering thing.

And like limptimtim I don't think I'm getting full boost,my max spike isat 16psi... I've got the N75J valve too...