turn and burn

Before you say it, I checked the FAQ.

Now to my question. I have a 90fc with only a cat back N1 and an apexi intake filter other than that she's stock, now when driving in any gear, at 5500rpm it's surging like it needs more fuel and won't gain any more rpm. Now at 5500rpm before i had this problem, would feel like i was hitting a power band. Is it my secondary injectors kicking in to give me the power band feel or what?

I posted this ? before on the 2nd gen forum but no clear answers accept guys talking about their 3800rpm problem, any impute would be greatly appreciated.

Thanks

turn and burn

bump