Slow4.8 silverado

Old post but I’m having the same issue as you @Juice75 I changed fuel pump fuel filter plugs and new wires changed tps and it just feels like Im driving up a steep hill going up hill is ridiculous i uave to floor it to stay at speed limit and same thing if I let off the gas it slows me down as if I’m pressing the breaks any update? Did you ever find a fix?