I am talking about choking the intake, never the exhaust.....Creosote comes from the fallout smoke leaves behind, period! It may mean your wood is too green or is oxygen starved or a combo, some people have used the wrong types of wood. Does your smoke have to travel a fair distance before the exhaust? The further it goes the cooler it gets before coming out the stack, as it cools down it will drop microscopic particulates on the meat, these culminate into a somewhat greasy, black, bitter tasting outer layer....if this is the case I suggest lightly covering the meat with foil, NOT wrapping, and see if that improves the problem. You will find whatever is deposited on the foil would have gone right on your meat being smoked, we all want a little but too much is no good! Cover the meat after an initial smoke of 1/2 hour to an hour, play with it until you get it right for your tastes, good luck!!! Thomas