My 05 is showing po420--"catalyst efficiency below threshold". In looking at some previous threads, someone talked about extended warranties on the cat. I asked local dealer if this was true. Yes, warranty extended per federal mandate until June of 2013 or 80,000 miles. They weren't too pleased that "someone read the code" and that I knew about the possiblity of the warranty being extended. Isn't that too bad? I made an appointment for Friday morning. We'll see what the dealer has to say and what they will do. If they do replace it, I'm sure they'll use OEM and look how that worked at 72,000K. I'll post the resolution.

 

Good luck, P0420 is the most common trouble code and sometimes a PITA