i have a check engine light on and i took my car to autozone to have the computer scan my car and it said that the o2 sensors were not working properly anymore and it said something about the cata converter not working also.... now my question is should i replace the o2 sensors and the converter or just the converter????? i know this is gonna cost me a pretty penny so and answers would be appreciated!!!!

 

oem cats/02 sensors are pretty spendy, heard bad thing about bosch 02 sensors, i believe magnaflow has some oem replacement cats