Oxygen sensor questions

[Blackfrogg 1]

Wasnt too sure where the best place to post this was but here we go anyway.

Im doing the e30 m50 swap and instead of using the m50 exhaust manifold im using the m52 manifold. The m52 manifolds have a place for an oxygen sensor to fit into each manifold (2 total). The m50 manifold didnt have anywhere for an oxygen sensor to fit but from what i understand it had a place after the downpipe (1 total).

My question is do i bung both the holes in the m52 manifolds and put just the one sensor later down in the exhaust system or will it get a correct reading if i bung one of the holes and put a oxygen sensor into just one of the manifolds?

Thanks

[thorburn 121]

If it were me i'd just put it in one. Either way your making a compromise. From standard if one cylinder is running quite lean and another quite rich the ecu wont be able to see this.
this way you just miss out on an entire manifold from the start

[Blackfrogg 1]

Im not sure how these work exactly but i wouldve thought having just the one sensor in one of the manifolds would only read half the oxygen (hence the m50 having it after the separate manifolds and the m52 having one in each) going out and it would compare it to the full amount of oxygen going in? which would screw up the fuel to oxygen ratio

[antil33t 90]

It doesn't need to read the amount of oxygen coming out, it reads the oxygen proportion of the exhaust gasses.

so it can work fine on just 3 cylinders, assuming the entire engine is working perfectly.

I would do as suggested, bung both holes and whack one downstream.

also, do not bother buying a used one (saw your wtb thread) they don't usually survive being removed and it's not really worth it to save $50.

[Blackfrogg 1]

Thanks for the info I think I will do the one sensor later down the track. Yea I had heard as much about the sensors but figured someone might have the hook ups to get them cheaper than pelican parts