I got my 2003 Flex Fuel Chevrolet Tahoe that im planning on tuning for E85. I know it has a sensor that will adjust the fueling by the amount of ethanol it reads. I have my tune dialed in pretty good with 93 gas so do i need to mess with fueling once i fill up with E85 or is it going to be pretty close? Once i get at least two tanks of E85 throught my tank i was going to fine tune fuel trims and start adding timing leaving everything else with fueling alone. Is this right or is there more to it? Thanks.