1981 Oxygen Sensor

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Kurtamine_
Posts: 66
Joined: Sun Nov 18, 2018 8:55 pm
Location: FL

1981 Oxygen Sensor

Post by Kurtamine_ »

My 1981 633 csi US model originally came equipped with with one oxygen sensor.

Due to age and rust. I took it upon myself to remove the and replace the headers and down pipe. I installed Ireland Engineering headers which fit pretty well for the E12 chassis. The trick is now to fab a proper down pipe. My original idea was to have two separate down pipes per headers that would lead to a resonator.

Now my issue would be that if it were two separate pipes then I would need two oxygen sensors correct? Are the early model DME's that dependent on the oxygen sensors? Would it make more sense to "delete" the oxygen sensor, and if so how would I go about doing such a thing?

In the event that the DME relies on this one oxygen sensor heavily, then I would just create a Y-pipe section for the set of headers and do an oxygen sensor bung.

Let me know what you all have done! Or what has worked best/easiest. Thanks in advance!
'81 E24
'99 miata
'84 E30
'99 eclipse
GRNSHRK
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Re: 1981 Oxygen Sensor

Post by GRNSHRK »

Kurtamine, I've had dual 3 into 1 headers (Stahl long tube...) forever, and only one of them has the bung for the O2 sensor :-k

Now I do have to admit that last year, CA smog check did not like this arrangement and I had to jump through all sorts of hoops to get passed, but I don't think this arrangement has any effect on running at all =D>

The headers don't meet or combine their flows until the Cat [-(

And I would not suggest eliminating the O2 sensor either, surely the CPU (DME) is going to expect to see a signal [-o<
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86_6series
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Re: 1981 Oxygen Sensor

Post by 86_6series »

I'm also installing Ireland headers on my 86.

My research came up with installing an x crossover pipe.
CO bung can be welded into the x, getting exhaust from both
headers and an x pipe helps scavenge the exhaust.

https://www.jegs.com/i/Jones-Exhaust/52 ... S/10002/-1

https://www.autoanything.com/exhausts-m ... -vs-h-pipe

On this one, our exhaust is not one inline so the separate pipe
theory applies.

https://www.carid.com/articles/are-x-pi ... stems.html
86-635CSi
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Kurtamine_
Posts: 66
Joined: Sun Nov 18, 2018 8:55 pm
Location: FL

Re: 1981 Oxygen Sensor

Post by Kurtamine_ »

Thanks for the links! I will probably end up doing an X.

My original headers and downpipe was all inline prior to me removing it.
'81 E24
'99 miata
'84 E30
'99 eclipse
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