98 cavalier 2.2

My car is acting up...the check engine light comes on while driving and when stopped at a redlight i go to accelorate and it bucks and jumps and sometimes shuts off. i usually have to restart to get it running good. sometimes the check engine light stays on sometimes it goes off. when the check engine light is off and i take off from red lights it runs fine...what could this be?

Check for codes and post them.