98 surburban stall when accelerating

I've got a 1998 gmc surburban 1500, 5.7l engine, 2 wheel drive. It runs fairly well when cold but after about 5 minutes it stalls out when you hit the gas. The last few days it actually has died out a couple times. If you stop and shut it off for a minute and restart it it works fine for a few minutes and then starts the stalling again. If you maintain a constant speed it takes a while before it stalls but hit the gas at all when it's hot and it's like the gas is shut off. I changed the fuel filter and it still has the same symptoms. I also changed the plugs and plug wires and it didn't help either. I changed the fuel pump about a year ago also. It happened a bit about 6 months ago and we drilled holes in the cataletyc converters and busted them out and it seemed to work a little but didn't help much then. Any ideas would be appreciated.