I have noticed quite a bit of ,for lack of a better term, tar coming out the draft door this past winter, I just thought it was because the cooker wasn't level. I just recently leveled it out by putting it "up on blocks" . These have been mostly low and slows, except when I forget to check the fire and it gets away from me. I seldom use any wood for the birds, and sometimes use hickory chunks for the ribs. I wonder if a "smoke pot" like Szyz's would cure your ills Doc? Hey...I made a funny!