98 ram 5.2 help needed

Lol funny , I have a low speed , misfire under load. I just changed the cap, rotor , wires , plugs, TPS , MAFS , IACV , O2S along with douching the TB and new gasket , and reset the computer, and it's still there , I have a feeling it's either an injector or fuel pump, although there was evidence of oil pooling down in the intake manifold.