I have the stock secondary cat off my Elantra I should weld in, maybe find another smaller OEM cat to be safe. I know the Elantra with both OEM cats with 300k blew almost 0's on it's last e-test (Back when they had the sniffer)

Salomon, glad to hear you passed with cams

1993 TSi AWD
2008 Evo GSR
2011 Ralliart
2012 Ralliart
2011 RVR GT