According to my hypertech programmer I keep throwing a code that is p0670. This is Glow Plug Module Conrol Circuit. Is this something that is gonna leave me stranded and if so, is it something that I can fix, or does the dealer need to fix it. I have modified my exhaust by taking the cat and the muffler off and I really dont want to hassle with the service dept. over these items. Any help would be appreciate. When I start my truck , the glow plug indicator is almost instant, and the starting of the truck seems to have no problems so i'm not quiet sure how to handle this problem.