Thanks for your tip. However, I replaced the EGR valve and cleaned out the tube about a year ago. Turned out that part wasn't the problem. The old one was still good, but I replaced the EGR valve anyway for assurance.

I did get the "service engine" light when that code was thrown for the EGR valve. In my current situation there's no code thrown. Any idea why the "Theft" light blinks rapidly when I'm cranking the engine over? Is this normal? I've not noticed it before.

I feel the problem is electrical. The truck was running okay just before I shut it off to go into the store. Hmm...

-Jack