Engine idles either real high or real low speraticlypress gas stalls or hesitant on 1999 Chevrolet Express 1500

Code came back catalyst, mass air flow and egr stuck closed.changed mass air, pulled egr and cleaned with throttle body cleaner had alot of carbon but not stuck replaced o2 and now the engine turns over and will only start if I spray carb cleaner in throttle body. What am I missing

Asked by for the 1999 Chevrolet Express 1500
A working fuel pump!