2013 Focus St Throttle closes after 5k rpm

I'm having this issue when I'm at WOT I noticed my turbo air flow is more then the desired limit, this hasn't caused to much of an issue under 5k rpm, it will close the throttle partly for small periods, but as soon as it it 5k rpm it will close the throttle to almost 35% and I cal feel it when it does that. I can't seem to figure out how to fix this. if anyone can help me figure this out I would greatly appreciate it.

Under speed density I has changed map 10 and that fixed a lot when it came to drop off under between 3.7k and 4.7k but even with that I can't seem to figure out why only at 5k it does it.

I should also add- I have a catless downpipe with a straight pipe exhaust, I'm not sure what has to be changed in the tune file to adjust for that. I really want to learn how to do all of this stuff,
I'm planning on getting bigger injectors and big turbo. I want to learn how to properly tune for that stuff before I buy it.