2002 Nissan Maxima Crankshaft sensors

I have a 2002 Nissan Maxima GLE. The car is stalling while driving and with the AC on it runs worst. A friend put his code computer and reset it. He unplug both front and rear crank shaft sensors and car responded the same he said it should be idleing worst. He check his code reader and it said no faults found.
Why does the car act the same when crankshaft sensors are disconnect and why won't it read a code.