97 Saturn won't accelerate

[zxkitaxz]

When I push the gas down in my car it takes a long time (about 2 freeway off ramps) to accelerate to 55 mph. When I am driving the freeway it doesn't want to go over 70 mph and it runs at about 2 1/2 rpm. Also when I accelerate the rmps go up to between 3 and 4, sometimes 4 1/2 and then drop quickly. I have found that for awhile driving it in preformance mode made it less of a problem but now that is not working and I can't go over 70 mph.

I have already replaced the spark plugs and wires, air filter, fuel regulator, and fuel filter.

Does anyone have any ideas? I am thinking fuel pump??

[Cat Fuzz]

You could check your fuel pressure but it kind of sounds like you could have a plugged catalytic converter.