Sputtering while driving *update*
Yup. Finally got her on the road. I love it. She runs good, but it has an issue. While driving, the car rides smooth, but occasionally the car sputters while accelerating, often times up a hill. It never stalls, after a few seconds of it, it'll go back to normal. Mashing the throttle doesn't help it along much 
So what do you guys think? TPS? Fuel Filter?
Also, it seems a little weaker than I was expecting. Has some power, but not what I was expecting.
This is the 5.0 btw. I gave it a tune up like, 5 miles ago, as well as an oil change, air filter, and a complete brake system replacement
Oh yeah, one more thing. The gas pedal is a little stiff. I'm attributing this to the car's age, but just letting you guy know. It's not a problem at all, I was just used to my mom's 01 Windstar...