acceleration? fuel pump bad? help

Ok for about 2 weeks i have noticed a very much lack of power and acceleration and hessitation on my cougar...it seems like the rpms go up to about 4 or so to switch gears and it seems like it is struggling to get up to 40 mph i dont have any clue whats wrong i even took it to the dealer and they said they fixed it but it is still doing it so i have to take it back...can anyone give me some suggestions on things to ask them to look at? i was told it could be a bad fuel pump could this be?
HELP!!!!

First question....what performance mods do you have?

I do not have any mods to my car other than tinted windows and my system....no performance mods yet....do you know what the problem could be? :confused:

it's the tinted windows it causes a heat exchange between the glass and your intake runner which cause your air fuel ratio to be off.............................


okay now really it sounds exatly like your fuel pump. first replace the fuel filter if that doesn't do it then i would replace the fuel pump. it is a very very very common problem in new cougars.

I agree with Cougar4life......definitely check the fuel filter. Check with Neco forums because there is a post about how to get to your fuel pump without dropping the tank. Also, dont replace your pump with a stock one.....upgrade!

could be the o2 sensor....