P0420 2nd Gen OHV help

[Mordecai]

Check engine light came on, found myself with a p0420 code. Should I bother messing around with a new oxygen sensor, or should I take it into a muffler shop and see what they recommend? I've had one of the cats repaired already.

 

[96eb96]

Must be diagnosed properly, otherwise it is anyone's guess. If the cats keep going bad, there is some other underlying issue.