Does your PCM act like it,s sick every now and then?Occassioally my truck will run like the timing is retarded for a couple of days.Then one day on it's first start up of the morning it will run like a bat out of hell for about two weeks until it get's sick again.I have read on other forums of some other people complaining of this problem also.I was wondering if I should try and get another PCM since mine may be defective.I have also experienced this with a full tank,so that rules out retard close to empty.