[Jasmine]

Maybe disconnect the battery and hold the detached cables together for 1/2 hour or so. That would reset the whole system -- however, it will also mess up your radio presets and anything else user programmable.

 

[Jasmine]

I doubt any sensor can tell what oil you're using unless it's something radically different. I'm not sure I understood the question, but if I get your drift I think all sensors are replaceable.