I got the rotten egg smell this morning - guess I'm getting a hi-flow cat for Christmas...

The engine has also been stuttering/jumping a few times. I was thinking it was a coil. I also just had the b-pipe replaced. No CEL codes.

Would a bad catalytic converter cause stuttering? Thanks for any advice.

 

If the smell goes away after the car has been warmed up, I would consider it's normal.

 

Typically, a bad cat will cause a loss of peformance above 2000 rpm.