O2 vs Air/Fuel Sensors

[aa040371]

I have a CEL with (apparently really common) codes P0420 and P0430, i.e. issues detected with both catalyst system banks.

My 4Runner is a 2007 Limited 6-Cyl with about 150K on it...AFAIK it has original catalytic converter and sensors. So I think no matter what, I want to replace the sensors and then hope/assume they last for another ~15 years/150K.

But I noticed on parts retailer website that Denso offers both O2 sensors and/or air fuel sensors. So my question is: Do I have a choice between the two in my upstream/downstream banks, or are they meant for different places/uses/vehicles?

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edit: corrected number-of-cylinders typo

 

[MikeinNH67]

There is no 4 cylinder in the US for this generation but I see V6 in your signature. As for O2 sensors, the ones closer to the engine (upper) are the air/fuel sensors, the one below the exhaust manifold cats (lower) are the ones the computer monitors efficiency with. AFAIK, the sensors are basically the same with different connectors and length of wires it's just how the computer uses them. BTW, leaking exhaust up in the o2 area can set these codes so something to look at first. I currently have the p0430 code on my truck, it was intermittent in the summer but since winter fuel came out it has been solid on. Higher octane fuel can make these go away, but at a buck a gallon more, I'll pass.

This is what I see on Rockauto for an 07 V6. Looks like they are the same on both sides. Earlier years have 3 different part numbers.

DENSO 2344260
Downstream
$44.79

DENSO 2349051
Upstream; To 06/2007
$118.79

DENSO 2349026
Upstream; From 06/2007
$120.79

 

[aa040371]

Thanks, [MENTION=298412]MikeinNH67[/MENTION]. I corrected my typo. re: from sticker on driver-side door frame it looks like my car was manufactured in 12/06, so thanks for clarifying the part switch (WTH!?) in middle of model year.

Do you have ~$330 I can borrow?

 

[aa040371]

[MENTION=298412]MikeinNH67[/MENTION] : Follow-up, please: Is an O2 sensor socket required for removal/replacement? If so, how is right shape or size determined? (size is not mentioned on R/A "info" page for the sensors.)

 

[MikeinNH67]

I have a socket like the one below that works pretty well. You can also cut the wire and put a deep well socket on it assuming there's space. May even be able to borrow something from Autozone or similar. I have used things like vicegrips to get them off but not as much leverage that way.

Amazon.com

 

[aa040371]

May even be able to borrow something from Autozone or similar.

Amazon.com

Yep...Autozone loan program was what I had in mind (vs Amazon loan program, of course. : )

I plan on hitting the four threads with penetrating whatever a few times in previous week before attempting...so mostly was wondering if these O2 sensor sockets were generally needed, or were just a gimmick or nice-to-have. From you comment it sounds like it's worth a stop at Autozone to me...thanks.