I ran through the rest of the 100 LL, and put in premium, and it cleared up......I'm confused, I thought higher octane fuel was supposed to kill KR, not make it worse. :? Is it the lead?

Lead can kill an O2 in short order, and a Cat over a slightly longer period of time. You may have run a small enough (low enough) amount that it only coated the O2 enough that the follow-up fuel removed the residue from the sensor.

You might have just found your problem, AND saved the O2, but keep it in mind in the future.