P0420 and Catalytic converter that empty inside!!!
 

Dear RX enthusiasts please help!
About year ago my check engine light came on, diagnostic showed it to be P0420 "catalyst efficiency below threshold" and that was the only code I got. At that time I wasn't looking into that problem.
Couple of month ago I started to notice a lot of bad smell (burned gas) coming into the closed idling car, same thing on the traffic lights and whenever car was parked and idling, P0420 was constantly getting from the scanner.
So I started to look into that P0420 problem again and what I did is I brought my car to the mechanic, lifted it and unscrewed back oxygen censor, the one that located right into the catalytic. When I looked inside the catalytic - it was empty, completely. Mechanics checked that with the small LED light, they were able to stick it inside on its full length, about 15 inches. Both mechanics told me that their opinion is that insides of the catalyst converter got burned up and then blown out of the exhaust pipe, it took some time but now catalytic seems to be completely empty and clean out of debris.
I know that I still have warranty on my RX8, but going to a dealer (Giuffre Mazda)
was always too painfully - each time I felt extremely unwelcomed and not respected! But I guess I have no choice, hopefully they won't charge me for new cat.
My question is if anyone encountered anything similar to what I described?
Owner of '04 Rx-8, MT, 70K miles

I replied to your other thread. read.

yes plenty of times. most times the material is already mostly broken away or melted before the cel turns on.

should b covered under warranty i believe.....otherwise i think a new cat is like 1600 bucks or something ridiculous like that if not!

Since your still in your 8/80 Emissions Warranty and you don't like the dealer you've been using, go to www.mazdausa.com and find other dealers in your area. This way you won't have to pay for repairs.
The other option would be to install a hi-flow performance cat. They should be under $500 for the part. Here is one: http://www.rx7.com/store/rx8/rx8exhaust.html

Had that code pop up last night, took it to the dealer this morning and they replaced the cat (under warranty)...in and out in 45 minutes.

Your lucky they stock one. My dealer had to order a replacement each time.

Got lucky i guess, what do you mean each time, have you had it replaced more than once?