What could this be?

You could be driving my car down the road or on the highway or through town or stopping and restarting and you will have your foot on the gas pedal driving and the car seems like it lost its power and sputters and you take your foot off and press it again and it resumes its speed. Ive changed my fuel filter, oxygen sensor and put gas treatment and fuel injection cleaner in the tank. what do any of you think this could be?? please help!!!

Year? Engine?

If this is a Quad4 engine, more than likely the Ignition Coil Housing is failing around $60 not difficult to replace.

or other possible culrpits could be
cat converter
plugs
wires (unless u have quad 4 w/ IDI)
and even - in case u haven't checked - air filter
all things worth checking

Or your torque converter lockup. Look down on top of the transmission and you will see a 4 prong plug (usually blue in colour). Unplug it and see if your problem goes away. If it does, it is your torque converter and can be costly to fix. Many just leave it unplugged when they have problems and suffer with a bit of extra gas mileage.