It sounds like you may have knocked a vacuum line off or somthing like that. Easiest way to be sure is to ,,first look real good lol then jack up the truck or if it is high enough climb under it and pull the vacuum line off the modulator and see if it has suction while it is running,,,if it doesnt then you knocked it off and you need to look real good,if it does have suction then try this,( chances are you have a 700 trans and dont have a modulator valve ) BUT,,disconnect the battery then push brake pedal down 3 times ,,wait a few minutes then reconnect battery cable and then try it agin and see if that fixes it. sometimes the puter gets confussed and the text book says to not only disconnect battery cable to reset but also to push on brake pedal a few times as it will then fully clear codes. good luck