The sputtering occurs on high rpms around 6500-7000. It started to happen once the car was getting tuned, it prevented me from making a little extra power. Before the tune it had never happened. Since then i have changed the fuel filter,spark plugs and wires are also new. Replaced the ignition rotor, and ignitor and it still keeps sputtering. I'm thinking that it might be the coil or maybe the fuel pump cant keep up with the fuel demand at high rpms? Not too sure but really wanna fix this, because i cant rip the car through all the gears

 

First gap down your spark plugs
It can be tuned to rich for some contition and then have misfiring in the rpm
check with a wideband

 

A little bit about your setup might help. What engine, injectors trans exhaust etc etc...

Also;
What are you using for tuning?
• Engine management system - Chipped Honda ECU OBD0-OBD1-OBD2 or standalone system?
• Software - Crome, Neptune, Smanager or K-Pro
• Hardware - wide band O2, exhaust gas temp and/or cylinder head temp sensors?

If you were able to log data you should be able to determine where the issue is fairly quickly.