Stalling when turning

Kind of need a few more details. What speeds? What kind of turns; slow speed in the parking lot? Changing lanes on the highway? Standing still and turning the steering wheel? Only when the gas tank is near empty?

Was the battery recently disconnected or run dead? Do you get a nice "idle flare-up" to 1500 rpm when you start the engine?

I still don't know if the battery was recently disconnected for other service. If it was, the Engine Computer has to relearn "minimum throttle" before it will properly control idle speed.

I still don't know if you get the idle flare-up to 1500 rpm. If not, the air passage could be plugged with carbon or the automatic idle speed motor or wiring could have a problem. There's a way for your mechanic to test that.