Check engine light on for P0420

[misslomenzo]

Check engine light on for P0420, but freeze frame shows that Catalyst Mon is OK? Any ideas?

[GR1087]

Last year I installed a set of cheapo oxygen sensors from Amazon ($30 set) and wasted my money, after passing smog test in my state the sensors started throwing this code again.

Went to rock auto and bought two name brand sensors, I think NTK/NGK($80 set), and the car runs much better with no codes tripping anymore.

You get quality when you pay for it these days. Most of the time, lol.