02 Sensor - Time to replace?

[Thiazolium]

Just throwing it out. My car runs fine - no driveability problems, no crazy gas mileage problems etc., however, I've read that O2 sensors can degrade over time. My car has pretty high mileage and the sensor has never been changed. Change it or leave it be? Thoughts?

[jtgh]

they get slow as they age and at 100k they work ok,but mileage drops 1 -3 mpg.
you can get a new PNP Bosch on Fleebay for $50

need pn, just click the o2 sensor on my fast sensor test page.

[jtgh]

pnp is plug and play, no soldering.

[Thiazolium]

Thanks - will give it a go.