I'm at work and after I get off Im going to go have the code read, but I figured since I have nothing else to do Id throw this out and see if anyone has an idea.
I have a 2002 F-250 6spd 4x4. There is no check engine light when I start the truck. Once I drive for awhile and the engine gets up to temperature the check engine light comes on. Then once she is shut off and cools off it turns back off. I replaced the thermostat, temperature sensor and the fuel filter just as my regular maintenence, but that still didn't fix it. Anyone have an idea off the top of their heads?