I'm not saying that all turbos will have this problem, although Jim himself sortof implied it. I have seen some turbos do this and the problem disappear when cats are installed. It is my opinion that the turbos that have this issue have a problem - be it just old age or an improper rebuild. Otherwise, we would see it in every case. You and I are on the same page.
My call to JWT was to try and get their opinion on the matter. I dont stand to gain anything from any of this and my intent was not to gain - it was only to put the information out there. Hope this helps bro..