i have a 91 geo runs good until it warms up then it will die when slowing down at stop signs and wont start back up. i have but new o2 sensor on and put new spark plugs, new air filter not sure what the problem is.

I came across similar symptoms once on a '93 metro. The coolant passages through the throttle body were plugged, causing a false-cold reading from the coolant temp. sensor mounted in the TB. Ran strong cold, ran like garbage when warmed up with intermittent stalling/hard starting.

-Matt

so how did you get the throttle body coolant passage unclogged? is there a cleaner you can put in or how did you tear it apart to unclog?

I believe I used brake parts cleaner and a coat hanger.