A few weeks ago my cat became less effective, I noticed smoke coming from my chimney one day (for a few minutes) - white smoke, but the firt time I have ever seen smoke once cat was engaged since getting my Fireview years ago- and I started smelling smoke. Found my screen was completely clogged. Cleaned it and decided to remove and clean the cat, even though it looked fine in situ to visual inspection. I was shocked to find it completely clogged with fine white powdery ash, which fell off/out when I lightly tapped the cat upside down on a piece of newspaper. Brushed it with a fine natural bristle brush and replaced it. That was after about four weeks of burning. Have not had any problem since. It has been colder out, though. Keep a close eye on the screen. If it gets at all obstructed I will immediately clean my cat, as I also will if I smell any smoke. I have not yet had a subsequent problem. , and I am wondering if the shoulder season burning may be a bit more conducive to fly ash accumulation in the cat/on the screen, and may account for the trouble everyone is having with the stainless cat this year. I do need slightly more air in my stove when temperature outside are moderate or when it is raining, and the increased draft does make the fly ash visably fly about a bit in the firebox. Maybe if this was a normal cold winter the stianless steel cat would perform better. Those of you who have found fluctuation in the performance of your cat: can you recall whether good performance has been on cold days? From my experience, for anyone who is having an issue with any smoke smell/poor cat performance, first thing I would do would be let my fire burn down, get the stove top temp to about 120 and then take the cat out and inspect the distal side...even if you have done so recently. I suspect that in some circumstances this cat can clog VERY quickly. But it is very easy to clean, and in my experience works fine when clean.