only had it happen to me once as well, with the slider open ,windows down, thought it was some one in traffic at first ,then realized it was mine, but it went away before I could find the source or what it was... did smell like a jet/turbine , I think the truck was spraying fuel into exhaust to help on a regen because the egt's was not hot enough? don't have gauges so I'm just guesing, but I know they can add fuel upstream in the exhaust, I think its to get the catalist hot? kinda like a gas car running dead rich the cat will even glow it gets so hot from all the raw fuel? don't know hope we find out so i know weather or not to worry about it . I think dodge should have a technical class on these trucks and tell the owners what these things will and won't do/capabilities and functions.... as we pay more attention to what these things do than they think, were not like most drivers who go: was that light even on? was that bad? you know the just get in it and go type.