'94 ram 1500 problems

I just bought a Ram 1500 5.2 from this nice old lady and she screwed me over big time!!!! I drove it 62 miles and started to hear a noise that was a clang which got worse as I drove it. Then suddenly I took it on the highway and it started spittering and spuddering and backfireing and would not accelerate, even with the peddle to the floor. After a tow bill and careful consideration from my dad, who was here for the holidays, he concluded it was the caddaletic converter and muffler was clogged. I bought the parts and had them changed and was excited when I heard that the noise was gone and it seemed to be running great. Until of course it warmed up on the way home and was it's usually ugly self with the spittering and spuddering and loss of acceleration. It took it about 5 to 10 minutes to get real ugly and just not go. I pulled over let it cool for an hour and got it home but it wasnt a pretty drive. No check engine lights have came on at all... Could it be as simiple as a clogged fuel filter or is it in the distributer? Like the ECM module? Please someone help. Has anyone else had problems like this. I'm Desperate to get this fixed before my husband comes home from a deployment. Thanks.