93 buick lesabre stalls at stop light read for me info?

Alright so I a while ago I was having some problems with the car bucking when it shifted gears then it went away (college student so no money to spend on my car). So just today I was driving for about 30min and I stopped at a red light the check engine light turned on and then the engine shut off.. No shudder just stopped. The funny thing is that I was able to start the car back up and when I was driving the check engine light shut off. It was only when I wasn't accelerating (pushing on the gas because the car stalled going down a hill) and idling that the car shut off on me. One of my friends looked at the car and said that it might have a cracked header.. Does anyone have any suggestions? I could try taking the alternator but would a cracked header loose that much pressure for the engine to stall like that? Any ideas on what I can try first that is cheap (can get the alternator at a parts yard but have never changed a header)... I know with something like this it can be a shoot and miss but I really wana have it crap out on me in the middle of the road anymore...