Just had to have my fuel pump replaced in my 2017 flex fuel sr5 cm. Truck would hard crank start and would only get running after a few tries, overall idle, rev and other fuel issues. Basically ran like crap. Service manager told me they were an issue from the day the truck rolled off the line and are only replacing them if there is customer concern. It is a problem with identifying the new fuels and setting the system accordingly. Anyone with a newer flex fuel Tundra should be taking it in to replace, they are all problematic.