What would make my car sputter then die when driving at slow speed?

OK so I have a 99 Pontiac grand Prix gt with 250,000 on it. Recent maint. history: new
serpentine belt, new tie rod ends, oil change, front and back breaks, new tires, i think
that's it. FYI left fog light is out and either a head light just went out or the break light
cuz the right blinker is faster then normal just with everything else going on i have not
been able to check which one is out. anyways  about a week ago i got new tires after i
got a flat, later that night i hear what sounded to be a tire leaking but all tires are fine. a
friend suggested vac hoes maybe leaking so he looks around wiggles hoes and the
noise stops, cool; well then service engine soon light comes on. Then a few days later  
with a half a tank of gas on im driving along the car starts to sputter like its going to die
but it doesn't. next day same thing only it gets a little worse and more frequent. Then
yesterday just got in, started driving turned at stop sign and it starts sputtering and
dies for the first time since it started sputtering a day prior. so i pull over turn off key
start freaking out turn car back on it starts fine i start driving and it does it again. same
thing pull over turn off turn back on start driving this time turning around and going back
home down the block. the car made it home fine no with out further issue and its been
parked since. it is low on gas but not on E. a friend said maybe a sensor so we
disconnected the battery for 4 minutes but the light was still on. sorry for my lack of
knowledge and grammar pertaining to the car but if it were better i probably would not
be asking for help :)