After chasing down an O2 sensor historic fault that I believe may have been moisture related, I then asked my self........self I wonder what the life expectancy is on these bad boys, especially the rear cylinder with higher head temps.?

 

Moisture related? How so? Unless you take one off and drop it in the toilet I don't follow how it could be moisture related. These exhausts heat up so much, so fast that any moisture would be burned off quickly. O2 sensors have seemingly been a low fail item. Having said that, I am going to swap mine out over the winter, as they are at least 4 years old. I worry about them getting out of spec due to age/heat. What sort of problem were you having? Did you replace sensor(s)? and did that correct the problem you were having?

 

I should have clarified that the moisture issue occured at an intermediate plug style connection that I have routed along the bottom frame rail for the rear cylinder. It's a Tmax system with autotune using the 18mm wide band sensors. The problem started after going through a very heavy downpour and driving wind with lots of water everywhere. Opened the connector, dried it and reconnected with dielectric grease and so far problem solved.

When I started the troubleshooting process, I thought a bad sensor could be a possibility which are now 2 years and 10,000 miles old with the majority of the miles in high heat conditions; hence my original question as to the expected life of a wide band sensor. Your point of drifting out of spec. is well taken and now I'm prompted to hook up with the laptop and see how both sensors are reacting. I'd rather be proactive than reactive to a failure. Plus it's an opportunity to hangout in my shop, drink beer and fiddle with my girlfriend.

Thanks for your input.