It looks like you ran into what my concern was for making my own gauge on the scanner using the MAP sensor input. A 2 bar map is going to start off with vaccum, hit mid point or around 2-2.5 volts, then read boost up to 1 bar or roughly 14.5 lbs of boost. The gauge should read 0-200 Kpa and is more accurate and then you can convert your number with the tool menu in the scanner, you just have to subrtract 14.5 or 14.7 from that number to get your real boost. 1 bar is atmospheric pressure, 2 bar is that number times to or will read to 14.5-14.7 psi over atmospheric pressure. Your gauge would have to start with vacuum and then go to zero and then show boost to be right and this is something I never played with too much as I couldnt get a straight answer on the best way to set it up.
