In reply to alfadriver (Forum Supporter) :
Interesting.... that's the opposite of what we were told in a Bosch new-technologies seminar, that basically boiled down to "our new UEGO sensor technology is so fast, that the computer can keep switching to a minimum, so that smaller catalysts can be used". Theory being that big slow swings mean you need a large converter to store and release all of the oxygen for cleaning the exhaust, so the shorter the swing period the less catalyst capacity you will need.
The takeaway we got from this, incidentally, was that new tech = smaller cats = much lower fault-tolerance, so a misfire or a little oil or coolant consumption is far more likely to be a catalyst destroying event compared to an older car with a cat the size of a small muffler.