Moving on to number 2 Mike. When i turn the car off when hot, i am getting a constant clicking sound from the exhaust area that lasts for about two minutes. I rent cars 5 times a month and i know you do get a clicking noise from that area. But this has the sound in the same two second intervals for the two minutes. It is not occasional. Any thing that could be "sticking" after i shut down like a solenoid?
Unless you could directly put a finger on it, then I would say its the exhaust cooling off. But then, their is a first for everything and might be a solenoid. I say bring it up with the dealer while you have your CAT in for warranty work.
i would look at the evap solenoid, for the clicking, not likely the cause of the running rich though. that could be a number of things from air filter, maybe a failing o2, maybe fuel pressure regulator, maybe you have a bad plug or two.