Dodge Ram 1500 V8

I have a Dodge Ram 2000 V8 , I love it, but for the last 3 months I can be driving and suddenly it will shut down, everything will work but the fuel pump so I brought a new fuel pump(by the way it has a filter screen inside the fuel tank.) it still does it, I changed out the fuel relay, and it still does it no one can seem to know what the problem is, one person told that the catalytic converter is to close to the fuel pump and when it gets hot it shuts down, and it needs a shield, , if I disconnect the wiring from the fire wall it will take less to time to cool and will start right up , I am lost because I am so afraid that it will shut down at any given time so I always have to drive on the side that has a place to stop, I am a wreck when coming home from work, HELP