99 Suburban wont accelerate

I didnt know how to explain the problem I am having in the header title

Here is what is going on 99 Chevy 5.7L starts fine idols fine. Starts out driving good. When you push the accelorater to get going though, it cuts out. As if not getting fuel.

Fuel Pressure is a 60 psi so please dont say fuel pump. Fuel filter and pump just were replace. Fuel Injector Spider was replaced a week ago and that took care of 1 issue that the truck was having. intake gasket also replace as well as Crank sensor and spark plugs, Distrubotor cap and rotor are new also. As this vehical had many issues but now it is down to just this last major 1.

Push accelorator and no power at all, no take off. Acts like it is about to die.

if you lightly try to speed up it usually will get going ok then. But if you push down normal or hard on peddle no power and boggs down.

Also the exhaust system has been completly removed so it is not Plug cats.

I presume that the truck was stalling before you removed the exhaust because w/o the oxygen sensors connected, the ECM will run in open loop mode and illuminate the check engine light.

I'd check your throttle position sensor, then the IAC valve, then EGR valve.

I am having the same problem with my 97 Z-71!!! smooth idle, no codes, goes decent if you slowy give it gas, but craps out when you need to go. My truck was running fine and then I went to go around a big truck one day and it hasn't run right since. I do know that it is not the mass airflow sensor. If you happen to find out what it was.PLEASE WRITE BACK AND SHARE. Ditto here.....