Wideband O2 questions

Forum for discussing how to install MicroSquirt(TM), choose and troubleshoot sensors, wiring, and communications for MicroSquirt (TM) and MicroSquirt Module(TM).
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Schmarf
MegaSquirt Newbie
Posts: 1
Joined: Mon Apr 22, 2013 6:29 am

Wideband O2 questions

Post by Schmarf »

MS noob here so please bear with me... I've already searced for similar topics but didn't have any luck. I will be converting a small single cylinder air cooled engine from carbureted to EFI using the uS controller. I will likely be using a narrowband O2 sensor in the long run but am interested in using a wideband for initial tuning purposes. I've already acquired a few different narrowband O2 sensors which use M12 x 1.25 threads. On this engine the exhaust manifold is incorporated into the muffler, leaving a 1" ID x 2" length pipe for the exhaust manifold. An M12 x 1.25 bung has already been welded into this manifold leaving essentially no room for an additional M18 bung. Here are my questions:

1. Do any wideband O2 sensors exist which have an M12 x 1.25 thread? I have not been able to identify any such sensors.
2. If answer to #1 is no, I could use an M12 to M18 adapter fitting but this would locate the sensor out of the direct exhaust stream. Has anyone had success using an extended bung like in this scenario?
3. I am assuming the answer to this is yes but would like to verify in any case: The description for pin 34 indicates some sort of wideband sensor controller like the LC-1 is needed to get the 0 to 5V required output, is this true or is it possible to wire a wideband sensor directly to the uS board?

I appreaciate any input you may have!
dontz125
Master Squirter
Posts: 375
Joined: Mon Jun 29, 2009 1:00 pm
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Re: Wideband O2 questions

Post by dontz125 »

1. None I've found, but I haven't particularly looked. Most are in the M18 range.
2. There ARE 'extended' or deep-well bungs, typically used in turbo applications where the gases bearing on the sensor would otherwise be too hot. This suggests that using such a bung in a non-turbo pipe might lead to the sensor running too cool, but this probably just means the heater will be on more.
3. The uS cannot read a WB sensor directly; you need some sort of controller. The new Spartan sensor / controller combo from 14Point7 is a fairly economical piece of equipment.
750steve

Re: Wideband O2 questions

Post by 750steve »

Does a different bung ned to be used in turbo applications then? My exhaust will only be 6 to 8 inches long
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