odd idling and bad smell

I was in line at the car wash and all the sudden the car starting idling weird, hard thumps every so often. It didn't die, and I got it home ok but when I parked it I smelled somthing like rotten eggs, and my SES light came on. It wasn't overheating, the oil pressure was at 20, and the RPMs were fine, any ideas on what happened?:uhoh:

Rotten egg snell usually = plugged catalytic converter.

That's what I was thinking, but would that cause the odd idle?

As he said, a plugged cat...most likely cutting airflow.

Well we're checking for codes tomorrow morning, so... Thanks guys :o)