The other day I was driving and the check engine light came on, there was no difference in driveability. Then all of a sudden the truck shut off on me with no warning signs. I was able to start it back up but the RPM's were all over the tach. Could it be the idle air? Any advice would help, thanks.

 

You need to check the code.

 

rpms all over the tach are one thing, actually idling all over the place is another, pull the codes and do a little diagnostics

 

Probably the Idle air, had a similar problem with my old explorer. You can try cleaning it with brake cleaner and re installing it, but they are not expensive to just replace it.

 

you can check by tapping it with a wrench/hammer good a few times, that will unstick it at least temporarily. but that doesnt explain the cel coming on while driving. go get codes pulled for sure.