The spreadsheet that was posted appears to work (in calculated something, haven't tried in practice), but I got a bunch of conversion errors since I'm not in the newest version of Excel. The worksheet basically just does

I didn't think that worked in practice because of the way the numbers were derived. I would think you would need to reverse the equation that converts the 0-255 byte value to the "AFR" we see in the map.

In the end, it might just be a better idea to rescale the MAF to get the #s to match up...

 

i tried it... it allows you to enter more than one cell. you can just copy and paste your afr map into it.