[SoCal LS-L]

Well something you can try is to get a transmission funnel and put the nozzle down into your fuel tanks inlet..... listening for the fuel pump whine. Since you said it stalls while idling too, you should be able to listen to hear if your fuel pump stops right before the car shuts off. If so..... suspect the relay or wiring to the fuel pump, or the fuel injection fuse and related wiring. If it stays on until after it stalls, its probably an air/fuel metering problem or crank/cam sensor malfunction.... which should have turned on the MIL.