I had this problem shortly after puchasing an 05 with 16k miles on it. From reading here I thought I had a blown head gasket or a leaky egr cooler. Mine mostly smoked at each red light leaving a big puff of white smoke on take off. After 2 tanks ( from 2 diff gas stations: both did same thing) the smoke quit. I read in the manual that getting air in the lines from a fuel filter change could cause white smoke. Thinking maybe they replaced the fuel filters just before i bought the truck. So the question is, have you changed your fuel filters recently, maybe allowing air in the fuel lines?