[dcb]

You are ignoring the elephant of incredibly few tests being performed and not using A-B-A testing to begin with. You started with a conclusion, and that is never good science. You jumped to this conclusion based on two tests, one with the ECU in a not-ready state. You said you cannot explain the data, so stop and think for a minute. I'm not saying you are wrong, but it has het to be demonstrated and quantified, you still use terms like 75x while demonstrating that the cat stays fairly hot between pulses...

Is there more pollution w/p&g? As a percentage of fuel used? We don't know. Using less fuel results in less c02 generally speaking and there are a lot of wastes upstream of your tank. Your experiment has no controls.

For all we know you have a lot of oil blowby and your car need lots of extended time at temperatures to keep your cat clean on your car. I don't know what would be in the gas causing your cat a problem needing 100s of miles to correct. But the condition wasn't sufficient even with p&g to trigger the onboard self diagnostics, and it might even be the o2 sensor that is fouling and not the cat. And there were misfire codes...