I also want to know the temp that the cat is running at, to avoid the damage they say will occur at sustained operation over 1500. I don't want to be anywhere near that, although I was at 1400 on a couple of occasions with the Buck 91. At that temp, the cat is bright orange, almost going yellow, and you can't see the cell walls any more.The only thing you need to know there is whether the cat is active or not so you know when to close the bypass.