gladiator,
Try disconnecting your batteries Negative ( - ) terminal for about 5 minutes.
This will clear the computer.
When you reattach the battery cable, start the engine and let it idle until the cooling fan comes on.
Make sure all of your accessories are turned off, like your Heater, A/C, defroster, lights, etc...
This allows the computer to re-learn how to idle the engine.
Now you can go out and drive it again, and see if the light comes back.
If the light comes back right away, you definitely have a malfunction.
It can be something as small as a leaky gas cap to something bigger.
Depending where you live, you might be able to meet with a local CEGer and get your codes read, if they own a scan tool,
or try stopping by a Pep Boys or AutoZone and ask them to read the codes for you.
Don't buy anything until you come back here and tell us what they told you.
We wouldn't want you to buy anything unnecessary.
Pete...
98.5 SE Sport Duratec ATX (P66L) Black Clearcoat on Greystone
DOB 11/21/1997
DOP 12/25/1997
PIAA 510 Super White Driving Lights
SVT CAT-BACK EXHAUST (No Resonator)
DiabloSport Chip (LPQ4) - Engineered To Raise Hell
Too many other mods to list...
Sounds sweet, runs quick...
Crazy Horse Dyno @ 121.4 WHP/129.6 TQ