Changed the glow plugs in my LBZ Duramax Diesel and learned a few things. First, why did I jump into this project? Whenever it was cold out (which is often here in Michigan) the glow plug would come on and when it went away the Check Engine light would stay on. So I pulled out my spade tuner and read the code which was ECM P0672. Review what the code is its defined basically everywhere as a semi generic code but with some specifics like what cylinder to troubleshoot So which one is the #2 Not that it really matters since when you are changing them its always recommended