Car is hessitating

96 cadillac deville. This has happened 4 times in the past 70 miles. The car stops accelerating and I have to pull over. It wont let me rev the engine and bogs down to about 500rpm when I put the accelorator to the floor. I just got a brand new fuel pump and fuel filter and had new plugs and wired put on last spring. Someone said it might be bad gas ive put 2 cans of heat into the gas and still getting the problem. No engine light is comming on and im not getting any codes on the obd.