Yes, resetting clearing , erasing, deleting... each system has it's own name for it.
The scanner he is using is a third party scanner... that may or may not make a difference. I know from experience that some codes cannot be erased using "quick delete" (BMW DIS name for it) You have to go into the module and actually erase within there.
I'm not familiar with the diagnostic system he is using so I can't say if it is capable of doing that.
As far as driving in a straight line , I don't know it that is necessary or not.

If you can find the values, it may be possible to test the voltage or resistance coming out of the sensor