It's missing really bad. Throws a couple codes, 300 306 400 415 and some others too. I think it may be something in the EGR stuff. CEL is on and sometimes starts to blink, never seen that before. Just put in a new set of plugs to try and fix it but id didn't seem to affect it at all. This problem has progressively got worse and really need some help.

 

There is NO EGR on these trucks.
You need new plug wires too, www.apexperformance.net has the best price on the best wires, Magnecor.
Are you loosing any coolant?

 

No no coolant loss. I checked the dipstick and no milky oil. Head gasket was my first thought.

 

What are the "some other" codes?

 

do what spike said. magnecor 8mm and new plat +4 plugs and if you are loosing coolant its time for HG's and you can install the new 8mm and plat4's when you do all the fun gaskets