O2 sensor placement on 3FE conv

[wheelz64]

I did a 3FE conversion on my FJ40 and opted to go with no O2 sensors. Not a smart move on my part, I know that now. So I need help in placement of my O2 sensors. I attached a picture to show how my downpipes flow. Not a lot of room for the bung, should I put it on the lower piper after the exhaust goes into a single. First picture shows the 2-1 connector and the limited room. Second photo shows underneath, could I put it that far away.
Any help on this would be appreciated.
Thanks

 

[Engineer8000]

It requires one on each bank of three cylinders. The ECU manages the two banks of three separately. They are specific so be sure the front and rear are plugged into the correct plugs. This is about where they were on the old exhaust and they worked fine for years. Just a few inches down from the flange. The front one is kind of hidden behind the steering box heat shield.

 

[bobm]

Only had 1 on my 91 80 series. Just in front of cat converter

 

[Engineer8000]

@bobm good point. The 80 series had a different ECU so yes, if you are running a 3fe from an 80 series do like they do. Mine is from a 62.

 

[wheelz64]

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[wheelz64]

Thanks everyone, my engine is from an ‘88 FJ62, and it clearly has two based on ECU. My biggest question is how close to manifold can I be. As per image number one, I do not have a lot of choices. I am thinking right before 2-1 connector. Or do I need to have 2 new down pipes?
Thanks again.

 

[1911]

Only had 1 on my 91 80 series. Just in front of cat converter

Mine also.

 

[wheelz64]

Just wanted to say thanks to everyone that assisted and ih8mud posts. No more 21 or 28 codes but also had a code 22. So replaced the cold injector sensor and water temp sensor. Now no more codes. Cranked right up and is idling steady at 650. Wiring and corrosion are your worst enemy on these old cruisers. Pictures of now installed O2 sensors and the code 22 culprits.