Bad cat....will it throw cell 1?

I know my cat is bad…it has rotten egg smell when I gun it. But will it or should it throw a cell 1? O2 sensor code? Just wondering cause I changed my O2 not long ago and hope that it’s not that.


I had that same smell… replaced the cat and the smell is still there… I think my car is running too rich but I don’t know why… :think:

If your cat is bad, maybe it’s because your car is also running too rich causing the cat to clog and the O2 sensor to fail… what king of MPG are you getting?