Wondering if anyone else has ran into this. I recently installed my flex fuel sensor, when I enable flex fuel mode with the key on engine off it displays the new FEC .690. Seems to me the sensor is working and ecu is seeing a proper reading. I try to start the car up and I have to constantly feather the throttle to keep it running otherwise it will die. So I disable flex fuel thinking some how that's the issue. it shows the old FEC of .680 but is now doing the exact same thing having to feather throttle to keep it running, which never happened until I enabled flex fuel mode. Next I load my previous tune back into the box which does not have flex fuel enabled and the car fires right up and runs like a top. seems to me that somehow by enabling flex fuel mode I am corrupting my tune. Do I need to do an update or re flash the box ???