Weird problem

I have a 2000 GT with 91k, and it seems if I drive it over 30 mins straight it will start to sputter and stall under acceleration. The car will not rev past about 3000k, but the weird part is if I turn it off and turn it back on, it will be fine again for about 10 minutes before the whole problem starts again. I've noticed the problem occurs quicker when it's hot or I'm low on gas.

I've cleaned the MAF sensor, but that didn't work. I'm out of ideas. Anyone know what may be wrong?
 
If I fill it up it defnitely drives smoother for a lot longer than when I start out with about a quarter of a tank. It's been doing this for about 10,000 miles now. It's just weird that when I turn it off and back on it drives perfectly fine for awhile then the problem starts back up
 
Ok fuel filter has been changed but the car still drives fine for about 25-30 mins, and then it just starts sputtering, not accelerating. It wil go fine to about 3000RPM and then it just starts bucking and can't get past 3000RPM unless I barely it give it gas. But if I give it about 1/2 throttle is will start stalling, bucking. One of my friends said Barometric Pressure sensor...? I have no idea. But this problem is really annoying for longer trips. Even though it still fixes itself for about 10 mins if I turn it off and fire it right back up. Anyone have any ideas?

If it is the fuel pump does anyone have any suggestions for a quality one. I just have a GT with exhaust, and UDP's. Thanks for the help
 
My Cougar did this when I still had 1/4 tank of gas. I filled it back up and it fixed the problem. I went ahead and changed the fuel filter (it was clogged).

Since you already changed the fuel filter, I would also look into your catalytic coverter being clogged. They also have a 100,000mile warranty. I'd check the fuel pump next.

Something I found on "howstuffworks"

A catalytic converter can also fail because of:

Bad exhaust valves on the engine
Fouled plugs causing unburned fuel to overheat the converter

Sometimes you can tell that a converter is clogged because you don't go any faster when you push the gas pedal. Also, there usually is a noticeable drop in gas mileage associated with a clogged catalytic converter. A partially clogged converter often acts like an engine governor, limiting the actual RPMs to a fast idle. A totally clogged converter causes the engine to quit after a few minutes because of all the increased exhaust back pressure.
 
to check cats use a vacuum/pressure guage. hook into hoses going from DPFE sensor down to exhaust, should read 1 PSI or less at idle and then rev to WOT momentarily and read guage should read around 3-4 psi. If cats are stopped up will probably read 6 psi or better.