is300 Sportcross lambda sensor

[NormanB]

When my engine management light came on, my Lexus dealer diagnosed a faulty lambda sensor and as the car was still running well (only 90k from new), it was agreed that the work would be done at annual service/MOT, due in only a few weeks. In the meantime, as the dealer price was rather steep, I asked my local garage for a price, and as it was much less, I got them to do the work. The light went out, but only for a few miles, and when I took it back their analysis readout showed another of the four lambda sensors not switching (a sign of failure). This seems too much of a coincidence. But if they had replaced the wrong one I would not have expected the engine management light to go out at all. Could there be some other fault that is blowing these things up?

[Paul Brooksbank]

The receiver unit? Therefore, nothing wrong with the sensors! 

[gdh300]

I think might just be age related; it's a pretty hostile environment for a sensor over 15 years. My old IS300 had the P430 error for ages, even after one sensor was replaced. But like you say, it ran perfectly and passed a couple of Mos with the "fault" still present (clearing the EML first, of course!). You could end up like a friend of mine who replaced sensor after sensor only to find it was the cat was just performing a bit below par.