SO I just got done doing a big tune up I did the following:

New Fuel Filter
New Spark Plugs
New Fuel Pump (walbaro 255lh)
Changed all Fluids
new air filter element

Here are my mods Catless 3" exhaust, 565 sti pinks, header and up pipe, plus a cold air intake.

Now my car never did this before but wants I hit 5000 RPM it feels like I hit a fuel cut and it will not accelerate any more, plus it feels reel doggy on the lower end. I was running a MBC but took it off because my wife started driving. I never heard of running to fat being a problem but one person gave me the idea of changing the injecters back to stock I don't want to do that but if it will make my car run better (ecutek and vf34 will be installed after this problem gets fixed)

My question is did the ecu finnaly realize there was no cats and put it into limp mode? Could I possibly have gapped the spark plugs wrong? Can anyone help me out here please I am desperate?