Yah, the thing with the AFC is that you can trim(take away) fuel without any problems, but when you try to ADD fuel, you can only go so far before getting a MAP sensor code. Once you go past about +10-15% fuel enrichment, the extra 10-15% the AFC adds to the MAP signal in order to get the stock ECM to add fuel will tript he MAP sensor malfunction code. The ECM will think you're seeing boost, basically. You might be able to get around that with a voltage clamp, but I don't know how you would get that to both clamp MAP voltage, yet still have the ECM add fuel.