Replacing an 02 Sensor

[calinissan]

Hello fellow Pathfinder owners:

I am looking to replace the aft Bank2 O2 sensor on my '05 Pathy (4.0L - edited typo).

I've been looking for how-to pictures or videos on the net and have little luck finding a resource.

Can anyone out there help me out on how to do this myself? I am no mechanic, but I do change the oil, replace spark plugs and coils, and hell I can even change a light bulb. However, I don't know where that specific Bank2 second 02 sensor is, and how to best access it for replacement.

Lastly, I understand I need a special O2 sensor removal tool, is this correct?

Any insight is most appreciated.

[forgottenzone]

The driver's side bank would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2.

So bank 2, 2nd sensor is the one behind the catalytic converter closer to the rear of the vehicle.
and you shouldn't need any special tool you should be able to use open wrench. just disconnect the O2 wire plug. slide the correct size wrench over the plug and wires and that should be it. will need some elbow grease behind the wrench if it has been on for a long time.

[calinissan]

Thanks for the response - is it accessible from under the bonet or underneath the car?

[smj999smj]

Under the vehicle.

[calinissan]

Got it, thank you. Will be working on it over the holidays and will post up pics for others' reference.

[disallow]

you mean 4.0L, right?

[calinissan]

you mean 4.0L, right?

Yes, my mistake ... I meant 4.0L (Original post now corrected)

I just went under there, and I think I located it. This is the sensor located underneath the Driver Side seat, is this correct?

.

[calinissan]

(bump) to confirm that the rear/downstream Bank2 sensor is the one located/accessible underneath the Driver Side seat.

[smj999smj]

That's the one!

[calinissan]

I just got to it and replaced it today. I had to lift the front wheel a bit with the jack so I could have some movement space. It was difficult to get the sensor to come loose as it was screwed in there pretty tight, there's not much wiggle room underneath to get the leverage I need, so I had to use a mallet to tap on the wrench, and finally it broke free.

For reference of others who need to do it in the future: The exact location for Bank 2 Sensor 2 is under the vehicle, under the area of the driver side floor board/pedals. The sensor is on the top side of an exhaust pipe under there.

Tools I used:

- Adjustable wrench (I believe the size of the bolt is 20mm)
- Jack, to lift the front side of the car
- mallet, to tap the wrench (did not have to tap too hard)
- pliers to work with the wires and connectors
- flashlight
-anti-seize thread lubricant, applied to the threads of the new sensor (make sure none of this comes in contact with the actual sensor surface)

There are a lot of things in the way that would make the otherwise simple job a little bit tedious, but it's not all that complex at all. The whole thing, including some trial and error, and packing everything up took about an hour. Probably will take less than half that next time, but hopefully there's no next time.

Thank you to the forum members for your assistance.
.