Bucking at 5000rpm

Looking to solve a bucking issue witch happens 2-5th gear at 5000rpm to redline, I have a 2000 JDM BE5 What I have done:

-Checked coils and reggaped all plugs to 28thou

-Tried known good MAF

-Cleaned and tried replacing boost control solenoid aswell as tried manual boost controller

-Checked fuel pressure and Fuel trims, all is good

-Upgraded to an AEM 340 fuel pump, hard wired the pump for constant voltage

-Datalogged timing and it is not being pulled

-Datalogged knock sensor and it isn’t picking up enough to pull timing

-Cleaned all boost/Exhaust related solenoids

-Wastegate actuator spring is tight no play in shaft

-Vaccum tested and Smoke tested for boost leaks

-ECU mapped to run the shitty fuel in canada and peak boost upped to 18ps

-Tried plugging lines 10 and 23 to just get wastegate pressure and had NO BUCKiNG but was gutless at only 7psi

-Tried different cold air intakes

-Tried 3 different BOV’s, HKS, GFB, and stock

Probably more I tried but can’t think of, is there even anything else to look at? O2 sensors?

Do you have any way to do some datalogging or to checking AF/Rs?

Yes, I have been using an autel scanner and I don’t remember the exact number but my tuner said that they checked out

Is the fuel pressure good even under load?

 

 

If you haven't replaced the spark plugs recently and just checked them it's time to replace them. Also clean the ignition coils and if applicable replace the spark plug wires, old wires can over time develop small cracks and carbonate causing sparks to take unexpected paths.