I have had my truck for a week now and was passing a few semis yesterday. I romped on the go pedal and passed them, then let up on the pedal and romped on it again to blow out the soot. when I romped down again it went into a kind of dead pedal mode and every time I would press down on the pedal it was like no go. If I held it down it would like down shift and still no go. It only went back to normal after I pulled over, shut it down, restarted it and it returned to normal. Anyone tell me what happened and how to avoid it?