This morning the Malfunction indicator light (little orange engine light) came on and stays on. I have about 39000 miles on it. Should I rush in to the dealer or is there a way to find out what is really wrong with it?

 

Yep.

First do the oddometer trick to find out what code is flashing up.

Turn the ignition key to on, just so the instrument clusters come on and the engine doesn't start, 3 times ie off/on/off/on/off/on and leave it on.
In the oddometer area of your instrument cluster, you should then have a code displayed, which relates to the MIL error your now having.
Write this down.
Look up the error codes by doing a search on this web site in the tech section?
This should at least point you in the right direction. Plus, if you do have to go to the "steeler", you will have an error code to give him.

Also, try to disconnect your ground terminal on your battery. Leave your headlights in the on position to drain any residual power off.
After say 20-30 mins, re-connect the battery.
Run up your car and see if the MIL light is now off. You might be lucky..?

Don't worry about your idle being rough or it being slightly difficult to start. It's just the computer re-learning what to do etc and should dissapear if you blip the throttle a few times and take it out for a short drive.
Hope this helps.

Al.

P.S. If you still have the MIL light on aftyer all of this, you have a potentially serious error and it will need the "steelers" attention.
Do not run the truck too far in this condition.

 

I took the truck to Autozone today and they plugged in to read the code. They said it is P0157 which is an Oxygen sensor (sensor 2 in bank 2) The report states: The pcm has determined that the input voltage from oxygen sensor 2 in bank 2 is too low for current operating conditions

They said it is about 45 dollars for the sensor and a 15 dollar deposit for the tool.

About ten minutes down the road from autozone the light turned off. I dont know if the problem is gone or what.