upstream O2 sensor Life Span

[bluestream1]

It's common wisdom that O2 sensors only last 150,000 miles. Mine are well over that now. Any point in replacing them?

I have read in archived post where people have seen increase gas mileage after putting new upstream sensors in. I'm not sure how that can happen, as a sensor either works or it doesn't,

Any thoughts?

 

[2000StreetRod]

O2 sensor degradation

The performance of the O2 sensor gradually degrades - the maximum voltage output decreases and the minimum voltage output increases. Usually the max voltage decreases faster than the min voltage increases. The result is a wider swing in the air/fuel ratio which reduces fuel economy.

 

[koda2000]

a heated o2 sensor (which is what you have) is good for around 100-120k. the old unheated ones were only good for about 1/2 that or 50-60k.

 

[SoNic67]

The performance of the O2 sensor gradually degrades - the maximum voltage output decreases and the minimum voltage output increases. Usually the max voltage decreases faster than the min voltage increases. The result is a wider swing in the air/fuel ratio which reduces fuel economy.

^ +1. On my Sable (6 cyl) I gained some 2 mpg on highway. City - not that much.

 

[bluestream1]

Well, 2 MPG would pay fo rthe sensors in a short time...

Next question: Bosch or Denso preffered???

 

[drdoom]

BOSCH working good here.

 

[SoNic67]

It might not be 2mpg on Explorer due to the brick-like aerodynamics
Every 5mph over 65mph translates in another 1 mpg lost.

 

[bluestream1]

What is reasonable; 5% MPG improvement? Any less, and its not worth messing with...