Recently I had a problem similar to this. I replaced the fuel filter, which took care of the problem for about 2 tanks, then it reappeared. At one point it left me stranded. When the mechanic checked it this time, he told me my catalytic converter was running nearly 100 degrees to hot (though the flow was fine). Took it to the dealership and their answer was as weird as it was simple - the new fuel filter (nd now my pump) was shot because the little gasket that keeps all the junk at the bottom of the tank from entering the pump and filter had come off, there for letting all of natures garbage come roaring through my fuel lines.

They flushed the lines, replaced the pump and filter (filter at my cost, pump under warranty), and since it has been doing better. I still am having some hesitation going through the power bands (maybe the plugs are fouled now? ). But my fuel filter has been doing fine.