Could be several reasons, but the first one that comes to my mind is the IAC (Idle Air Control).
It could.
Do you have a check engine light on? I would consider the idle air control motor to be a likely culprit. You also might listen for the whistling sound of a vacuum system leak.
that specific, have the vehicle computer checked. hope it helps. duboff
The engine has problems; when the engine is put into gear it becomes loaded but does not have the power to support the load at idle. Have it scanned for possible faults/codes, run diagnostic on the engine, and/or tuning it up may help.
your fuel pump can be broken or your fuel injectors...
What causes a 1997 Pontiac sunfire gt with a 2.4 liter engine to stall when stopped at a light
you might have a vacuum leak in your intake manifold
loose connection at battery or pcm or ipc bad ignition switch too much crap hanging from key
Did the service engine light go on?Turn the ignition on and off 5 time and read the codes. eg. 1 blink--pause-- then 2 blinks--pause = code 12.You can get a list of codes and what they represent from the net. Check your oxygen sensor,EGR valve, also clean out your throttle body with carb cleaner.Good luck.
try cleaning the throttle body
Does it stall at idle, just after you start up? Does it stall when you give it gas - or take your foot off of the gas? Does it stall at stoplights, stopsigns, etc? Does it stall when the engine is hot or cold or warm? I would love to try and help, but you've gotta give me something to work off of!
Check your fuel filter/ pump. The pump is in the tank.