So i am hitting fuel cut in 2nd gear around 6psi @+/- 5000rpm. I have rtek 1.7 which has a built in FCD. WHy am i hitting fuel cut? I have check the tps make sure it is in spec and I check most of the electrical connection. What else can cause fuel cut?

 

what makes you think it's fuel cut? Unless there is a problem with the Rtek (not likely), you are not hitting boost-induced fuel cut. The Rtek 1.7 essentially deleted the code in the stock ECU for fuel cut. You have another problem, such as a clogged cat, sever ignition breakup, or serious detonation.

 

I cant redline my car, in 2nd gear i cant go past 5000rpm and in 4th gear 4500rpm. Its seem like fuel cut because it feels like hitting a brick wall and I know how fuel cut feels like. Also I am running a RB full turbo back.

 

im trying to think, and it doesnt make sense. My car was running fine after i got my car out from a shop. After i reinstalled my high flow cat to get the car smog it started to act up.

 

Most standard cheaper hi-flow cat setups cant withstand rotary exhaust temperatures. Throw a test pipe in it and see if it still acting up, arghx already mentioned possible clogged cat.