180 degree headers O2 sensors?!?

[christian moller]

Hello all,
I have built 180 degree headers on my LSA(E67 camaro 2012) in the Datsun 260z.
one thing that got to my mind is, what happens with O2 sensors in this case?
Two of the pipes from each side cross over under the engine and ends in opposite collector.
Is this a disaster for the ecu?
How does the ECU use the input from the sensors?
Are left and right bank on "their own"?

Thanks
Christian

[edcmat-l1]

Picked a heckuva time to think about that being as you've already built them LOL but yeah, I think you'll have problems. Each O2 sensor controls their own bank. You done cornfused them now LOL

[christian moller]

I was afraid of that.............

Thanks
Christian

[blindsquirrel]

screenshot.25-01-2024 11.36.37.png

The O2 sensors don't care which cylinders they are reading, the ECM just needs to know which injectors to add or subtract from to get the correct response from which sensor.

This will, of course, completely fk the injector timing (the cylinders that get changed in the order will be spraying at the wrong time). But you built the thing, you have to figure out how much wrongness you're willing to put up with.

[blindsquirrel]

'Closed loop' and '180* headers' are probably incompatible anyway, sort of like converting to methanol and then worrying about fuel mileage.

[edcmat-l1]

I was thinking open loop myself. Much as I dislike that. Aftermarket controller is always an option.

[christian moller]

Hmm, open loop could be a way but i agree, closed loop is a much nicer solution.
Seems like i have created some sort of stainless steel garden art........
I'll have to think this over, they are only tack welded so far.
Making ordinary headers make life SO MUCH easier
Thanks both for the input.
/C
20231229_130959.jpg

20231227_153135.jpg

[5FDP]

Eh, I'd just pick one runner from each side and put an o2 sensor in it.

See what happens.

[GHuggins]

Since it's a swap and a LSA, just run a stand alone that will accept 8 widebands. Then you can tune and have fuel control. A lot has to be modified for 180's usually including solid front engine mounting and since it's a LSA if you pulley it much it'll want to lean out certain cylinders anyway, so individual fuel control would be a plus there... Just another option.

[christian moller]

Hello,
i'll give it a try and see what happens.
Blind squirrel,
I'm looking at your pic and trying to understand what it is actually doing (a lot or reading )
I suppose that this is injector opening,A1, B8, C7, D2 and so on.

Thanks
Christian

[blindsquirrel]

No, it's just which bank's O2 sensor that injector is connected with. 0 is left or drivers side sensor, 1 is right side sensor. Or, "If I, the ECM, add fuel to this specific injector, which O2 sensor will the result show up at?"

Come to think of it, maybe that table doesn't change the injector firing order at all. Whatever, that table will have to be changed for closed loop to function with those headers, it might or might not screw up other things along the way.

[christian moller]

No, it's just which bank's O2 sensor that injector is connected with. 0 is left or drivers side sensor, 1 is right side sensor. Or, "If I, the ECM, add fuel to this specific injector, which O2 sensor will the result show up at?"

Come to think of it, maybe that table doesn't change the injector firing order at all. Whatever, that table will have to be changed for closed loop to function with those headers, it might or might not screw up other things along the way.

Thanks!
I'll look in to that when engine is ready for start again, i have only tested it on a pallet so far just to see that everything is alive.
It was tight with AC compressor and engine mounts............