I'm not going to ask WHAT the symptoms are of a bad catalytic converter; I googled it and have found the following:
Here are just a few of the signs and symptoms of a plugged/dead cat:
1. Markedly decreased low rpm power,
2. Engine runs a little hotter than normal at constant cruising speeds,
3. Exhaust leaks near header that won't seal in spite of new gaskets,
4. Bucking or hesitation while accelerating,
5. Cat's exterior surface temp cooler near outlet.
And that seems like the exact problem I'm having with my car. And it has no extra CELs, so I don't think it's an 02 sensor; and I logged my MAF, intake air temp, etc. in VAG-COM and it all looks fine.
So I'm planning on hollowing out my cat on Tuesday to see if that fixes the problem.
However, until then, what can I log on VAG-COM to verify or disprove that the cat is the problem?