97 Bravada hesitating

I have a 97 Bravada it starts up after it warms up and you drive it the truck starts to hesitate.When at a light you have to give it gas or it will stall.when you take off it hesitates and back fires once you get it going then its fine until you stop or slow down again.I changed the fuel pump a year ago and changed the oxygen sensor and it isn't no better.Any ideas would help.

my 92 did that too, turned out to be the distributer shaft was worn out. no trouble codes and it took awhile to figure it out. check it out before you start on the fuel system, much cheaper. it also could be something as simple as a stuck PVC valve, what have you done so far? have the trouble codes read.