My car will die when i slow down to a stop sign/light. it happens maybe once a month so it is very much spaced out. i took it to a machanic, and they could not find anything, al all, it goes in for days at a time. but anyways, do you have any idea what it might be, maybe a loose valve or something. again the problem is my car will shut down at a stoplight or sign, and the headlights will be on, all the lights work, just me car wont move. once my car even got very hard to steer, and press the brake.