O2 Replacement Schedule?
 

Spent the past hour searching the forum for a discussion on this question. My confusion comes from the way this is written up in the owner's manual service schedule. It could be read to say that the O2 sensor should be replaced one single time, at 60K miles. But I feel sure that I've come across threads in the past that suggest it should be replaced every 60K. It's been exactly 60K on my 124 and, although I have no complaints about idling and there's never been a CEL or code for O2, if it's time for a replacement it's time for a replacement. Since we have no emissions testing in FL, it's up to each one of us to know when a replacement is called for. What say ye?

BTW, 199K miles on the clock. Last replaced @ 139K.

That was back in the days when the longevity of O2 sensors were questionable and California was pushing for cleaner cars...smog?

Now days if they fail you get a check engine light.

Bosch still suggests a 100K life.....BUT in real life "most" live about 150K.

i think you will feel better if you replace it. However, must people would say, if it is not broken don't fit it.

OK, thank you. I will leave well enough alone for now. I'll get around to hauling out the multimeter one day and take some O2 sensor readings to see what it registers.

Does the accuracy of it degrade though affecting performance and fuel economy?

Yes...the resistance and values will change possibly sending erroneous signals to the computer. They will stay within value for a while as they weaken but it's typically not a "working/not working" issue. If you don't replace it, symptoms may arise leading you to think there is trouble elsewhere. Best of luck.

Interesting. I guess I will take some readings so that I know what's going on with the sensor. If declining fuel economy is a symptom of a degrading O2 sensor, I have that. Thanks for pointing that out.