Saturday night i was getting onto the expressway, trying to beat a 18 wheeler that was refusing to get over for merging traffic. As soon as i got into my lane and shifted into 5th and started cruising i got a CEL. so i get to where im going and i turn off the car and leave it to cool down for a few minutes, come back out to the garage and let it run a bit, and see it i can figure out what the hell happened. as i started it up it sounded like it initially had problems starting up, and upon starting it was idling at about 1200 RPM. i figured screw it and left it alone. So sunday i drove it around finishing some christmas shopping and it was on all day, left it for about 6 hours, and got back in it sunday night to go out and the CEL was gone.

Any ideas? let me know
Thanks.