Don't leave eggs in your car... they belong in the refrigerator. Eggs left in your car become rotten in a matter of days. By the way you may want to have your entire exhaust system inspected. You could be smelling sulfur from the catalytic convertor. Rest a sure something smells fishy.

Catalytic converters do not cause the smell, in fact the smell is an indication that it is working. Over fueling cause the smell! The engine is running too rich.

My bet is that you have an engine light on telling you exactly what's wrong.

No, it is not the gates of hell opening up.

Most likely an emissions problem.

Ask your mechanic to perform an emissions test.

Most likely, it is the catalytic converter. Ouch! They aren't cheap.

Could be catalytic converter but on older cars it meant battery was being over charged, have the battery and alternator checked at an auto parts store.

Its most likely your Catalytic converter you need a new one, Unless of course someone cut one before getting out "LOL"

That's often a symptom of a failed catalytic converter. It could also be a battery failure, but then your car wouldn't start at all.

I know this has been asked before but some of the people answering asked for more details so they could give a better answer. I have a 2005 Chevy Cobalt with approximately 110,500 miles on it if that helps at all.