still having problems!!!!!

I have a 2001 Mercury Cougar 2.5L, I have changed out the fuel pump, fuel filter, spark plugs and wires, and fuel rail pressure sensor. But I'm still having hestitation problems and its idling rough. And I don't have the money to keep running around trying to figure out what is going on with my car. Can someone please help me?:confused:

Is your check engine light on or coming on with the engine running? If not, does it come one when you first turn your key on before cranking(lets you know the bulb is good)?

the engine light is on, and when i go to rev it up the whole car shakes and then the engine light starts blinking.

the engine light is on, and when i go to rev it up the whole car shakes and then the engine light starts blinking.

Blinking CEL = misfire. Check the code and see which cylinder it is.