My girls neon is all messed up!

2004 SE auto, noticed almost everytime going into reserve to back out car sputters likes its gonna stall but only stalled in reverse once. also when driving up a hill sputters like it wants to stall. also while stopped at a light in drive car sputters and has stalled once all this started in the last week or so. it has 46k on it just replaced air filter, oil filter, alt and ps belts yesterday,plugs were replaced at 35k will be doing plugs wires and fuel filter today.
I saw alot of threads on this posted back in 2005 but no one ever listed anything that actually fixed the car.
Any help is appreciated Thank You.