[dcb]

except for HC, things generally got worse in the third test, after all the driving.

The reason I am interested in WHY you are getting these readings is because that has implications for what to do about it.

You assert it is the cat

It could be the ECU, the first run could be interpreted as a slightly rich mixture from what I can tell, and not the cat, i.e. a software problem.

It could be an o2 sensor.

It could be contamination from another system.

We simply don't know, not enough data or testing, why is this such a hard concept? You are claiming p&g makes long term changes to a cat, and really haven't demonstrated that except by repeated assertion. Make sense of the data first, I have posted links to numerous effects of catalytic converters under different conditions, the observed readings do not yet make sense to me.