I wouldnt mind knowing the answer to your problem aswell.
I have a similar problem where I hit a certain rev range and the car splutters, a bit like hitting the rev limiter. I have a power fc installed and I havent adjusted any settings since having it tuned as I am not 100% sure of what Im doing.
Did a bit of research and apparently the HKS wet style filters are no good for your AFM sensor. I just changed from a HKS mushroom filter to an Apexi power intake and I havent cleaned the AFM yet. Still havent noticed a difference with the splutter though.
Happens on stock boost (7psi) at around 5000 - 5500rpm and on 9.6psi at around 4500 - 5000pm. Wondering, could it be the fuel pump? rev limiter setting?
Also, what type of contact cleaner is recommended?
Sorry for hijacking your thread.