I had an early failure of one of the two lambda sensors in my 2011 Toyota Yaris that was driven for approximately 40 000 - 50 000 km at the time of failure. Fortunately, this was replaced for warranty. I became naturally curious why the lambda sensor failed.
The dealership offered no explanation for the failure, and I do not have the failed component so I cannot take a look at the old lambda sensor.
So, why would a lambda sensor fail?
Might it be a sign that there is something else defective in the car, or is the likely cause a manufacturing defect in the lambda sensor?
Or is it just normal wear and tear that a lambda sensor fails so early?
I assume the car has a heated lambda sensor as it's a quite recent car. According to Wikipedia, a heated lambda sensor fails due to catalyst depletion, but if this was really the failure mode then why would the catalyst deplete faster than usually?
According to Wikipedia, heated sensor lifetime is typically 160 000 km, from three to four times as much as my sensor lifetime.