2011 Ford Focus power loss

Im trying to figure out whats going on with my friends 2011 ford focus. It started losing power and refusing to accelerate. It would happen randomly. Sometimes it would run fine and then others u could put the pedal to the floor and the RPMs wouldnt move. It always starts right up. We took it to the shop and he cleaned out the Throttle body, He said if that didnt fix it we would need to replace it. we ended up replacing it when she got stuck 30 mins away bc the car wouldnt accelerate again.

I just put the new throttle body on and it runs much better (for now) but the thing that has me uncertain about it being fixed it the cart will not rev up past 3500 RPM. it doesnt seem normal.

i Replaced the Brake drums before this all happened and i forgot to switch over the ABS rings so we have brake light galore going on, is there maybe a safety feature that affects the cars performance when the “Check Brake System” warning is on?? its the only idea i got unless we need a fuel pump or something?

any ideas are greatly appreciated!!