O2 Sensor in 4000cc 6 cylinder

[omaromar50 Lurker Find all posts View Profile Close omaromar50]

Dears,

I have just joined your wonderful forum, and I am new to Land Cruisers.

Can you please help me to identify O2 sensors location on my v6 2008 petroleum and weather o2 or AFR?

Also I am DIY guy and need some materials to start understanding these cars. appreciate all your inputs.

[BiLLz0r Advanced Member Find all posts View Profile Close BiLLz0r]

There are 4 sensors in total. 2 O2 and 2 A/F. The A/F are pre the cats. The O2 are post the cats. The cats are just after the headers.

As far as parts info, http://www.japan-parts.eu is a great resource for understanding what's where and part numbers.

[brooksy78 Member Find all posts View Profile Close brooksy78]

They pre cat sensors are right between the block and the firewall pre cat and very hard to reach but doable. Post cat are easily accessed from underneath and obvious as they are directly behind the cat converters

[Wil Senior Member Find all posts View Profile Close Wil]

Wow, just looked up the O2 sensors and they are $220 each for pre and $160 each for post sensors!
So that's $760 for new sensors to try and save some dollars on a fuel bill?
Can they be cleaned and serviced?
How necessary are they?

[BiLLz0r Advanced Member Find all posts View Profile Close BiLLz0r]

Wow, just looked up the O2 sensors and they are $220 each for pre and $160 each for post sensors!
So that's $760 for new sensors to try and save some dollars on a fuel bill?
Can they be cleaned and serviced?
How necessary are they?

Try Repco, they were cheaper than that.
How necessary? Well without them you the engine light will be on and it'll run rich.

You wouldn't change them to save fuel. They either work or not and if not you get an engine light on. I had 1 precat sensor replaced recently as well as both cat's, fuel economy is no better but it is smoother.

[omaromar50 Lurker Find all posts View Profile Close omaromar50]

Thank you for everyone helped me,
Actually I was having problem with the post sensors reading on torque.
One sensor was having normal reading between 0.1 and 0.8 (changing) while the other one was always showing 0.1 or dropping to 0 and rareley jumps up to 0.5 then drops again.

I was suspecting that it was sensor problem, but actually it wasn't.

Troubleshooting steps:
1- exchanging both O2 sensors and checking if the problem will move to the other side or not.
but no change was observed. so the problem is not in the O2 sensor.
2- I suspected the problem has something to do with either the cat or the exhaust it self.
the Cat is very expensive, so it would be at the end of the list.
3- decision was taken to eliminate any exhaust issue.
clean MAF, AIR filter, throtle, check spark plugs and Clean the injectors.
Infact injectors cleaning solved the problem and the O2 sensor were back to work normally (within the expected range).
"removing the injector and cleaning them out side the engine"