I recalled there was quite a string of posts late last winter about 2-cycle pollution . . .
I got a new Tomos this spring, and it does have a catalytic converter. However, during the break-in period, I think running moderately never lets the catalyst get hot enough to work. At about 1000 miles, the pipe showed definite signs of plugging, and performance went downhill very rapidly after that.
Then, with the pipe still covered by warranty, I replaced it. Performance was good again. And now that I am running a lot at wide open throttle, or close to it, I see that the part of the pipe where the catalyst is gets hotter than the adjacent pipe, and no smoke at all and no oil comes out of the end of the pipe! Evidently, it's all being burned by the catalyst. I'm very curious how long the catalyst will last now . . .