Dig this one up again. I have decided that the refractory box rebuild and all the internal gaskets are on the must do list for next summer. During this midwinter warmup I checked the flue. There was about quart of black flaky creosote chips collected in the cleanout tee The pipe itself looks to have a uniform 1/8 "coating of brown ash with some patches of thicker fluffy buildup. Possibly gaps in the insulation around the liner. This is from about 1 cord of wood consumption. My wood this year is very dry - all of it 2-3yr C/S/S, some measuring under 15% on a re split - and I have been getting good catalytic light offs and cat temps running 1100F-1600F on most loads. So I can only conclude that a failing refractory or bad gaskets inside (damper, fireback) are allowing smoke to get around the cat chamber without being burned. Probably why we smell smoky odor outside even when the cat is burning hot. Which reallllly ticks off the missus. UGH.