Could be a minor issue like the one I had with my 01 4.4.

The SES light came on for no reason one day and the car was running fine with no hesitation, etc. A few days later it went off, so I thought it was probably the gas cap issue. Another couple of days or so and it went on again. This time I took it to the dealer and it turned out to be something on the intake manifold like a PCV valve or something (I'll search for the paperwork later) that there was a recall issued for. They replaced a hose and that was that.

FWIW, I couldn't tell any difference after they "fixed" the problem, just no more SES light.

Don't worry, if something was REALLY wrong I you'd notice.

Good luck!

GO FALCONS!!!!!!!!!!!!!