Pizzano

Hello folks , on my 98 I have Kooks headers with Kooks catted Xpipe, I noticed there is a plugged bung right before the passenger side cat
(picture attached)

question is is that location ok for installation of the O2 wideband sensor or is it to close to the cat, I know is suppose to be before the cat , which it is , but awfully close.

thanks for your time.

RedRiderZR1

Not an issue. Perfectly fine right there. Issue you are going to have is it being farther downstream than normal. Headers moving the Wideband down stream. As far as close, try putting a wideband sensor after the manifolds and before the cat on LS7 manifolds.. that is close. That's my setup, and no issues there at all.

Pizzano

Im running Kooks headers also and the bungs on the headers have the factory O2 sensors there , which is recomended.

Also Kooks tech rep just replied to my email and said them bungs were specifically installed where they are on the x pipe for wideband sensors,

(which I did not have that info when i posted this post originally!~!

Thanks to all

tblu92

As long as the wideband bung is PRE CAT you will get a very accurate reading---
They recommend however if you leave the wideband installed permanently it should be mounted above the 9 and 3 o'clock positions---as if it were installed lower when the engine is off and re started moisture often gathers in the lower positions which tends to foul the wide band 02 If you are only using the wideband for tuning it won't matter as moisture won't ever have time to accumulate

NormK

Am I misguided in being concerned that reading AFRs from only one bank might give a false sense of security by showing perfect (or at least acceptable) AFRs from the side being read, while at the same time a faulty injector is causing a dangerously lean condition on the other?

_

RedRiderZR1

That would show up in the narrowband O2 sensor on the other side.

Doug Doty

That is kind of your choice if you want to worry at that level, single wbo2 assumes all fuel is flowing and balanced on all 8 cylinders and you are sampling an average of 4. If you want ultimate safety you need 8 of them, 4 only averages one bank, one bad injector could still lean out a cylinder on either side !! On my last race car and ran wbo2 on each collector and also had a bung in each tube for random fine tuning of the carb. and understanding the richest and leanest cylinder differentials.

aaronc7

to further clarify some of the remarks here... take a look at your long term fuel trims and make sure bank 1 and 2 are pretty close. If one is way out then something is up. faulty injector, one side running rich or lean.... or maybe just a bad narrowband sensor. Once you confirm everything is working well, then I would just proceed with the tune as normal. I always tune AFR a little on the safe side anyways, so I'm not too worried about one side running a little leaner.

tblu92

A wideband reading between right and left banks is minimal---I would not concern myself with this issue unless this is a dedicated race only car and even then there is very little HP left on the table
PS On an old school SBC engine the side DRIVER's always read just a tad leaner as the firing order had cylinders 5 and 7 fire in succession However on a LS engine GM changed the firing order by swapping the 4 and 7 firing order ---This swap made the PASS side read just a tad leaner----I would then recc if you were to install a single wideband 02 to run it on the PASS side ---As this would error on the side of rich rather than lean by having the bung on the leanest side-----
With today's exhaust where most people use an X pipe or an H pipe ---this connects both sides together somewhat making the left to right readings of little consequence ( depending on if the 02 location is pre or post the X/H pipe----