Main o2 sensor? Which one is it? I know there's 4 of them!

 

With all these Lexus gurus, no one knows which o2 sensor I need to replace?

 

main o2 is BEFORE cat (it is in exhaust manifold).
there is diagnostic procedure at service manualt to determine with one (left or right is dead)
I had that problem and change oxy semsor. in my car driver side was dead.
If you stuck I can help you tomorrow.
Jerry

 

Thanks , Jerry for your help

Where did you buy yours from?
I would like to replace both, if it's not to expensive?

 

you can buy universal oxy sensor, just must rewire it to original harness.
I am living in Poland
25 code is main oxy sensor (left or right) lean condition. in my car it mean that one main oxy was dead.
if you want replace both mains there is no need for determine with one is dead. Just replace both. use universal ntk or another good quality oxy sensor. rewire it to stock wiring harness. that is quite easy.

 

back from the dead

did changing your o2 sensors get rid of your code 25 ?