My truck has no fuel sensor and the tune is set up for a virtual flex fuel sensor. That sounds pretty cool, just keep the lambda whatever it is with the original stoichiometric value and target values, right? I guess that's what happens but I also that it would back calculate the actual alcohol percent and report it in the alcohol percent pid. Wrong. It magically stays at 9.8% which is the value for E10 a/f 14.1. The target a/f ratios are all relative to the original 14.1 stoichiometric value. I guess I could do a math function and calculate the actual a/f and look up the alcohol% in a table but probably not. I'm going to install a fuel sensor and hope it's just a matter of toggling the tune to actual sensor from virtual and all the a/f table magically take care of themselves. Is it that easy? Was hoping it was well explained in the Tuning School book but I don't see anything.