2000 Ford Crown Victoria glowing red hot catalytic converte

I drove to new orleans and the day after I got here I blew my intake. Well I replace the engine with a 4.6 out of a mecury grand marquie. Noe the motor is causing my catalytic converter on the passanger side to glow red hot. I changed them on both sides and its still doing it. I have no ideal and need help plz and thank you.