Hmm... I'm not sure, but I believe the catalytic converter has to be one specific to the aveo. When i first purchased my Aveo the catalytic converter went bad and it would have cost me 700 bucks if I wasn't covered, but you can find some cheaper ones out there if you can find some money somehow. This is the cheapest part i could find (the cheapest website I trust at least) for it:

2004-2006 Chevrolet Aveo Catalytic Converter - Bosal 079-5177 - Natural, 49-state legal - no CA shipments, OE replacement

Good luck man!