Smelly Exhaust?

Black Sun 5.0

Founding Member
Mar 23, 2002
1,337
0
36
L.I., N.Y.
I have a brand new Magnaflow x-pipe with cats and noticed a rotten egg smell while driving it over the weekend. Is this normal for new cats? Someone told me the cats might be clogged, but they're a week old, so I don't think so. The engine and cam are also brand new.