I have a 92' pontiac grand am SE , it usually runs good on the highway , but once i get in town and come to a stop sign or if i sit and idle for a 15 or 30 seconds it will stall... It starts right back up but i would like to figure out how to stop the stalling in at stop signs and holding up traffic , kinda embarresing... Any help is appreciated..and when it stalls all the lights and everything stay on and all electric things are still working when it does stall ....

How many miles are on it? It sounds like the o2 sensor. It cleans up on the highway because it has more timing and more rpm to burn the fuel but around town it just loads up too much fuel.

my car has 175,000 miles on it, and where is the o2 sensor at and how do i change it and do u have an estimate on what it mite cost

try changing the ideal air valve. (is the check engine light on? if so then you might want to change the o2 sensors. but i'd try the ideal air valve first)