O2 Sensor

[TucsonDon]

I have a '06 explorer 4.0L that has 106k on it, at what point should I think about replacing O2 sensors? Are they one of those things that "if it ant broke don't fix it" or does there performance degrade over time and need replaced?

 

[JacobDaniel]

Hi, I think they should be good for 100K as I was told, I had 165K before mine went bad though.