I have a 03 2500 4x4 auto,with a torq dog, nothing crazy, here lately it has seemed down on power and in the morning it will fire right up and run good ,but if you turn it off it will not restart, it takes about 10 minutes of setting and then it will fire up and run again. also if it idles for an extended time it will die. I have a p0251 code and have been told that has something to do with the FCA, but will it cause the problems that I am having? low power and hard starting?