2001 Toyota Tacoma Repair Catalytic converter

New catalytic converters
2001 Toyota Tacom 3.4L V6 Four Wheel Drive Manual 122K miles

I have a 2001 Toyota Tacoma Xtra cab 4X4 with 122,000 miles on it. My bank 1 sensor 1 A/F ratio sensor went out 11,000mi ago. I Replaced it with Toyota OEM, but before replacing it I drove two weeks with the check engine light on. The vehicle wasn't driving poorly in any way so it didn't seem urgent in my opinion. I may have damaged my Cat Conveter in that 2wks. The check engine light came back on a couple days ago and I had the code read. Bad converters - and to replace them (front and back) Toyota wants $2000. I want to sell the vehicle, but want to fix the problem before selling. I don't want to cheat the next buyer by "just clearing the code" nor do I want to do anything illegal. Will an aftermarket cat converter AND a cleared code keep the light off and be a properly working system with the computer expecting OEM? (I do not live in CA and I don't live in a state that has annual tests for emmisions) I'm finding prices online that puts my total at $500. Eastern Catalytic and D.E.C. Even OEM online is $1500. I'm looking for a safe and cheap way out of this mess.