I did my every other week vent cleaning and found sticky creosote in the last few feet of my exhaust. Never had it before the only changes to the stove are my OAK put in between this year and last. I know someone will ask 3" pipe evl of 14. I let the stove go 2 weeks without touching it was dirty of course but the fire looked fine. Maybe a little too ashed up and bad airflow? Or could it be the damp air coming in from the OAK. The rest of the stove is dry and gray/brown ash.