Had the same situation happen to my Ford van while on a long trip through Montana .... I was always "topping off" the tank every time I filled up to go as long as I could between stops ... called a good friend who is a Ford mechanic and he told me to STOP topping off the tank and to NEVER overfill any modern car, let the gas nozzle shut off automatically and hang it up right then. Overfilling will cause the CEL to come on and over time, damage the Evaporative Control System on these vehicles. So, I cleared the CEL with a code reader, stopped 'overfilling', and didn't ever see a CEL ever again ....... lesson learned.
