I've never checked for pulses in the exhaust at 2000 rpm. I tend to doubt they would be noticeable, but I might be wrong. @cardoc ?When at idle/revving to ~2k should I be able to feel the individual exhaust pulse from each cylinder?
I also wouldn't jump to doing anything with the cats until there's better evidence one or both might be faulty.
Look forward to the pic/data from the KOEO test.