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Wideband sensor help

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Old Nov 7, 2018 | 12:53 AM
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Default Wideband sensor help

So I'm trying to install my wide and sensor and I ran into a question. if the sensor has to go before the cat and I have a cat on the downpipe of each bank, where does the sensor go? Should I have one per bank or do I just pick one?
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Old Nov 7, 2018 | 10:07 AM
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I assume you are using the WB for tuning?
If no space pre cat for the bung, post cat is fine. The cats barely affect the readings.
Either bank is ok.

Ron
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Old Nov 7, 2018 | 10:53 AM
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I had mine after the cat. I only used one side also. of course doing two is better, but i only did one.
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Old Nov 7, 2018 | 01:54 PM
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Correct, the wideband is for tuning. I'm sure there's room for it pre cat. Really? I figured the cats would mess everything up. But out of curiosity if I were to have to put it post cat should I keep it in one bank or can I (or would i want to) put it after they dump into one pipe?
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Old Nov 7, 2018 | 02:09 PM
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Originally Posted by Kevin Fodge Jr.
Correct, the wideband is for tuning. I'm sure there's room for it pre cat. Really? I figured the cats would mess everything up. But out of curiosity if I were to have to put it post cat should I keep it in one bank or can I (or would i want to) put it after they dump into one pipe?
i try to put it about 18”-24” from the manifold or as close to the head collector as you can. Cats don’t affect it.
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Old Nov 7, 2018 | 03:38 PM
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There IS a difference between putting an O2 sensor pre- or post-cat. The cat uses O2 to oxidize CO into CO2 and HC's into water and CO2. Using that oxygen will lower an O2 reading post-cat.
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Old Nov 7, 2018 | 04:29 PM
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Originally Posted by G Atsma
There IS a difference between putting an O2 sensor pre- or post-cat. The cat uses O2 to oxidize CO into CO2 and HC's into water and CO2. Using that oxygen will lower an O2 reading post-cat.

well i based what I typed on two things.
1) I called the manufacturer. They said I could put it after the cat. It would work just fine.
2) deleted my cats and saw no noticeable difference.
It seems like theres one crowd of people who have never done it and says it can’t or shouldn’t be done.....but they aren’t basing that off of them doing it themselves. Then you have another crowd that has done it and says that it doesn’t matter either way and they have tried it themselves. Not trying to pick a fight, I’m just trying to give my personal experience because I ran mine after car for about a year.

****edited to “try” and avoid sounding like a jackass*** lol
And heres some other opinions




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Old Nov 7, 2018 | 04:47 PM
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Sounds like if the mix is stoich or richer, it does not matter. BUT if it's lean, the converter will use that O2 to burn off HC/CO. THEN there will be a difference.
True, the O2 sensor will work either ahead/behind the converter, but I bet the readings will be different.
I'm not trying to start a fight here either. I just know that O2 sensors both ahead and behind converters will read different. That's how the ECM know how efficient the converter is.
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Old Nov 7, 2018 | 05:00 PM
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Originally Posted by G Atsma
Sounds like if the mix is stoich or richer, it does not matter. BUT if it's lean, the converter will use that O2 to burn off HC/CO. THEN there will be a difference.
True, the O2 sensor will work either ahead/behind the converter, but I bet the readings will be different.
I'm not trying to start a fight here either. I just know that O2 sensors both ahead and behind converters will read different. That's how the ECM know how efficient the converter is.
you do make a good point. I’m not sure how it still works , but mine did.
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Old Nov 7, 2018 | 07:05 PM
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I think it matters depending on what wideband setup your using. I’m running a Ballenger AFR500V2 wideband, and it is very specific about being pre-cat.
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Old Nov 9, 2018 | 11:02 PM
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Thanks guys! I'm definitely going to try to run it pretty cat if I have room. I haven't had a chance to get under and look yet though
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