Just curious if that is how it is suppose to be.
I was on mmhg. I changed to option 1 one PFC and it changed to kg/cm.... I zeroed it out with FC Tweak and it looks something like this.

 

Yeah, that should be correct right? mmhg is a vacuum measurement and kg/cm2 is a pressure measurement. So the PFC will switch between the two depending on if your manifold pressure is in vacuum or boost. I believe the options you're changing in FCEdit are just adjusting the scale and offset of the voltage coming from your MAP sensor. If it used to read mmhg when the car was off it was most likely reading slightly in vacuum due to the old offsets. I think this is the question you're asking...

 

Yes that answers part of the question. Just never saw it before. Much appreciated

The other question is the actual scale value.
I read a lot on the Apexi 3 bar from back in early 2000s up till recently and it is suppose to be a plug and play with the exception of selecting option 1 on the commander.
This is not true in my case.
Mine started with the stock value.

I ended up using a scale value of 6579 and started with an offset of 3000.
Ended with an offset of 2864. Car runs smooth so I guess it is ok? Lol. I am too ignorant to understand. I am learning though!! I guess I need to log some runs and make sure this is ok. The gauge vs the commander is off by about .4psi. Also I need to verify it is in the proper "cells" I guess.
Again it runs good and smooth and the afr seem good.