How often should O2 sensor be replace? Local auto parts store indicates replacing O2 sensor every 50M miles.

 

50m Miles?

 

50 million miles - wow, that's some industrial grade O2 sensor!

Seriously, about every other year or 50k miles is about right.&nbsp It's cheap when you start using generic O2 sensors with pigtail bare wires with a crimped connector.&nbsp It's cheaper than swapping spark plugs!



-Ted

 

If you don't replace O2 sensor every 50K miles, will gas mileage and performance suffer? If self-diagnosis checker (code 5) does not indicate problem with O2 sensor, replacement is unnecessary?

 

Too many variables...
If you keep the O2 sensor "clean", they can last over 100k miles.&nbsp The problem with O2 sensors nowadays is that most modern gasolines have additives that leave all kinds of nasty deposits on them - all that orange and pink crud on your old O2 sensor is deposits from gasoline additives.

When O2 sensor performance degrades, they become lazier to react.&nbsp This can hurt mileage in the long run.



-Ted