[DanG]

You've got an '02 Cougar, which is returnless. If it's not a severely clogged fuel filter, it's classic fuel pump failure symptoms. The giveaway was that she almost died on you until you let up off the gas.

When you hit the gas, the ECU sends a command to the fuel pump to increase line pressure, and adds timing accordingly. Trouble is, the fuel pump for whatever reason can no longer supply the extra pressure needed during moderate to heavy acceleration - Demand exceeds supply, the car runs stupid lean, and sputters out on you.