Just to add to the information base...
I got a steady CEL Friday the 24th while driving around town...doing nothing extrordinary(sp?) in the way of driving. Couldn't get into the shop until Monday, but the car sure did run great for those couple of days...smooth idles, easy pull aways from a stop, no hesitation, etc. I did notice an excess gas smell though. Anyway, shop pulled the code...Catalytic Converter efficiency. They reset the MIL and flashed with "latest flash". Now I know I had the M flash already, as it was done as part of my 5000 mile service back in Oct or so, but they claimed there was a newer one (I see from Rx8club that there is).
Everything has been fine since, but I get a call today saying my parts are in! Parts!, what Parts?!
Apparently (I say apparently because the service writers didn't know anything about it and it wasn't in their computer records) when the shop guys called the case into Mazda, Mazda Corp. decided I needed a new Catalytic Converter just to be safe...so the shop guys told the parts guys to put in the order.

Guess I'm getting a new Cat....wonder if I ought to get a Cat-back at the same time :D

 

I've got mine set to go in Thursday. Symptoms sound similar...eerily. My cel also came on on the 24th...been driving around since, cause of course the dealership wasn't open til monday, and then couldn't take me til Thursday. Glad it's not something serious (I hope.)

 

The code was most likely a P0420..

Has your car flooded in the past?

 

No, I've never had a flood...the shop guys asked me the same thing. I figured I had a misfire or something, since there was no perceptible issue...the light just came on while accelerating onto the freeway (no, I don't drive redline...4-5K shift for reaching highway merge speed).

The oil smells of gas pretty strongly as well...which was another reason I thought misfire. I'm going to get the oil changed early....


Edit: I had a "Cat Performance" code come up about 10 minutes after driving it off the lot when I bought it back in May. I had the flash level that had the known issue with the Cat tolerances being too tight. Dealership flashed it the next day and I haven't had a problem since. I mentioned that to the shop manager as well.

AT

 

Wow...thats exactly what happened to mine as well.

 

Followup for this issue: I had the Cat replaced and the after-action paperwork cited the cause:
"Replace bad cat converter, loose part inside, internal failure"


AT