P0420 bank 1 code

Bank One is Passenger Side - Blocked cat will cause overheating and misfires - #4 is also on The Passenger Side You usually replace the banks in pairs - So replace the Both On the passenger side and replace both O2's also to protect your INVESTMENT in Cat's

Thanks for the info, I appreciate it. Will I do any major damage driving it until I can get the money to fix it?

Your O2 sensors are fouled with carbon from the cylinder #4 misfire. Fix the misfire first then as suggested, replace both two O2 sensors on that side. Each sensor is about $50 dollars. A new cat is about 1,000 to 1,200 new. Start with the misfire and O2 sensors first. Unless your ignored the misfire for a long period of time. This would cause the cats to be fouled with excess carbon and lose their efficiency to do their job. Good Luck

Magnaflow cats in pairs for around $200-$250 for 96 tc

EASTERN CATALYTIC Part # 30383 ECO II Direct Fit and EASTERN CATALYTIC Part # 30384 ECO II Direct Fit at RockAuto for 148$ Canadian each! ;) (not legal for California or NY though)