2001 Durango 4.7 Won't start

Okay, so I was going Christmas shopping yesterday, and after driving about 1/2 mile, my "check engine" light came on. I quickly pulled over to check it out, and after finding everything in order (plug wires, starter, batter terminals... etc) I hoped back in and it wouldn't start. Battery is just fine, but it wouldn't start up...

Hoped in it this morning to try it out, and it started up no problems. "Check engine" light was still on, but went ahead and drove it home. After the 1/2 mile, I shut the motor off, and tried to start it again. Same problem.

Any ideas why this is happening?

Merry Christmas everybody.