MAP SENSOR will not make the car die . more then likley its the pass system (anti theft ) there is a chip in the key could be the wiring in the steering colum . c/k to see if the anti theft light is on on the dash board

There is also a possibility that its your on board car alarm. Some cars alarms will activate a kill circuit if the alarm isnt deactivated before putting key in ignition... Sometimes to get past this we will use the key alone to lock the door, then a few secs later unlock the door and try starting it... Sometimes it works. Im not saying the map sensor cant cause this as well, but its another possibility...