Ok just got this truck and was under impression head gasket and injectors were replaced. has 143000 on it. I have the dreaded...p0540 code. when I was coming back from Indiana with it lost power on highway when a/c was on. reset when I turned it off. Since been home have replaced fuel filter. Code is back on...unrelated I think. It is starting hard (slow) almost like dead batteries but went to advance and they said they were good. I will try them individually to see if they are both good. I will also check grounds. a little frustrated....and nervous. thank Rw1650