Been shutting off while driving. It mostly does it while you are idling down?

Hello,

This could be due to a faulty crankshaft position sensor.
The crank sensor sends the information of engine oration to the ECM.
Over time with heat and vibration for the engine the sensor can lose its internal calibration. This will cause it to send faulty information to the ECM. Which can trigger an engine to shut down.
It can happen at any random time.
This may or may not turn on the check engine light.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor
https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.