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Oxygen Sensor In Cast Iron Exhaust Manifold

Captain Obvious

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Did they ever put an O2 sensor in the 280Z exhaust manifold?

I thought I saw a pic of a stock cast iron exhaust manifold that had an O2 hole cast into it, but now I can't remember where I saw that pic.

I checked the fische and didn't see anything like that, nor did I see any reference to a sensor, but I'm no expert with the fische.

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Thanks Jim,

So the 280Z never did, but the 280ZX did?

I found lots of pics of the ZX turbo manifold and that's not what I saw. The one I (think I) saw looked like the 240-280 manifold. I don't have the 81 FSM loaded, but I'm assuming the 280ZX NA version looks basically like the previous years?

Wonder if it bolts right up to the later 280's... I would like an O2 sensor, and can't think of a better place than one that's already done. I could weld one into my header, but I'm thinking I might downgrade to cast iron. :stupid:

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Thats right, 280 no, 280zx yes.

The O2 Bung on the turbo is not on the exhaust manifold, but on the cast iron down pipe which is immediately after the turbo. The turbo is bolted to a 4 bolt flange cast into the exhaust manifold, which is nothing like a 240-280 manifold other than at the head flange.

Using a 81 and up NA exhaust manifold would give you the 02 outlet on the manifold.

That said, 02 weld on bungs are available at any speed shop or online. Weld it into your header collector, or if you go stock, put it in the exhaust pipe right when all the down pipes finally end up as one pipe just past the Y.

Cast iron manifold on a mostly stock engine is just fine, and much quieter in the engine bay and cabin, if that's your thing. Good luck.

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Thanks again Jim.

Your stated advantage for the cast iron manifold is exactly one of the reasons I'm considering going back. Less heat in the engine compartment is another one. I suspect most people would think I'm nuts to go back, but I seriously doubt I've got any performance gains with the header. Only advantage I think I have is the "coolness factor". As in "Cool! You've got a header in that thing!". I'm so past that... :D

I've got the stock manifold for my car. PO put on the header, but included the old parts in a box. I was just thinking that if I was going to be putting on a cast manifold, it wouldn't be any more difficult to put one on that already had a bung built in (like 81 and up NA). And I could put a bung in the exhaust pipe, but I always thought the closer to the engine and the hotter the better?

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