replaced throttle body sensor, still having reduced engine power light & dies, was told it needed flashed ?

So many problems with this vehicle and this issue Reduced power... the BCM under the seat having corroded connections, possibly fuel pump issues, throttle sensor connector with loose wires! issues, accelerator pedal sensor issues. I suggest the GM tech2 scan tool get the answer. Reflash is like updating your PC Adobe, Java. etc... you get it. Contact your dealer make sure they don't want to charge you a fee for a factory firmware Update!