So at those RPMs when the ports open up you'll feel an acceleration increase right? Cause when I hit high rpms it feels like my car hiccups then takes off lol

 

Sounds like a "sometimes stuck“APV assuming this sputter already happened at the time when you have the hollow cat.

 

So I thought it could be my cat since it had 60k on it. I ended up buying a brand new stainless steel 3" agency power exhaust system with the dual resonated midpipe and the sputter only went away in 1st gear and still does in 2nd, 3rd, 4th, 5th an 6th gear. Wires and spark plugs are going to be replaced again but not going to replacing the new coils.

 

The same just happened to me but I think its my coils because for a while in my 4port at around 4 grand it will feel like vtec and I know my coils have over 50k miles on them but my sputtering doesn't start at reving but at idle in up and won't go past 6k any ideas not meaning to take over you question but an answer might help both of us

 

Hey there, i am having the same issue car runs awesome until I go hard on it. About 7k it starts to "buck" and seems as if there is constant power, I was thinking clogged cat so i purchased a full turboxs exhaust. That didnt help so i cleaned MAF changed Coolant, Changed Oil, New plugs, cleaned fuel sock so on so forth. I also have an AEM CAI. This issue is driving me crazy as it feels like im driving my winter car that is less powerful any ideas? on a fix? I am only able to get 89 octane here where i live