Gunna have to monitor this one. No CELs yet but I was heading to the gym earlier and the garage stunk like rotten eggs. No smell while driving, no bog down, but when I got back from the gym I could smell the exhaust had a "burnt" smell. Who knows, could be nothing, but I have seen a bunch of S2's on here having some CAT issues so I will have to keep a watch. Gotta go to the store a little later today, gunna drive it hard and see if I can see the cat glowing (i know its not a good way to tell, but if it is then that will go ahead and solidify that htought)

 

a good cat will smell like crap when you just start it but it shouldn't when its warmed up.
when my cat failed, a CEL told me the cat efficiency was below threshold.

 

I had both Cats fail on my 1998 M3 Sedan twice! OUCH!!!

Hopefully RX8 cats are less expensive than BMW's.

 

yeah u should have a CEL go off if there were something wrong there. I have a burned something smell coming from my car from time to time I just thought it was exclusive to the 8.

 

^^ Yea i think thats all it is. I dont recall smelling it before but driving it is fine and shows no issues at the moment. I'll just keep this noted in the back of my head in case i feel something different with the car.

 

The CEL cat code will come on when your cat already failed. If you want to know if it starting to fail, you need a scan tool that can access "Mode 6" data. Every once in a while, plug the scan tool in and check the catalyst switching ratio and see what the numbers are. You will be able to see how good or how bad the cat is doing at that time.

I did mine at 10,000 miles. Numbers are still very good.

 

^ thats good to know, thanks for the tip. The smell seems to have gone away so maybe it was just my mind playing tricks on me, or left over garbage inside the cat. Who knows.

 

The rotten Egg smell comes from unburnt fuel deposit on the cat that when heated up with the element inside the cats creates sufure gaz, as the cat will age up it wont create that gaz anymore, the fuel will just heat up and burn away, until then if you drive it slow and let it idle alot it will smell like that, nothing unusual