The not-so-Grand Prix stalling problem

This past summer, my parents bought me a used 1997 Pontiac Grand Prix so that I would have transportation to and from college. The past couple months it has begun to, at completely random times, stall out while I’m driving it. Just right there in the middle of the road it goes k’chunk and dies. Unfortunately I have had to become very adept at using my hazard lights, as it becomes necessary to wait at least couple minutes before it will start up again. On other occasions the RPM gauge will die, yet the engine continues to run. After having it for a week and running all the codes on it, mechanics were still unable to get it to stall out successfully. Apparently only I, and occasionally my brother, have the knack for it.(and no, this is not associated with our driving abilities) Does anybody know what is wrong with this Not-so Grand Prix of mine?

Sounds like an electrical issue. Is the negative cable on the battery and chassis tight? What happens after the car stops, can you crank the engine or no?

Were there any codes?  If so what were they (not the names, but rather the numbers like P0123)? 

Does it ever happen with a cold engine, like the first mile after starting?  How about weather?  How about a history?  Is the maintenance like pugs and wires up to date?  Do you park on a hill?