O2 sensor readings, left vs. right bank

zenboy99

Founding Member
May 12, 2002
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Madison, WI
For you guys that are datalogging, do your Kam values always read the same for left and right banks? Mine have always been identical, even when one O2 wasn't switching back and forth over 0.5v.

After I installed my Systemax intake and 75mm throttle body, my left and right bank were 5% different from 1.2-2.6 volts on the MAF. At idle both O2's read the same. This has been happening for over 60 miles so far, originally after the install they were identical, now after ~100 miles they're different.

Also just want to make sure, the left O2 is the driver side right?
 
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zenboy99 said:
Interesting. Do they differ by as much as 5%?

Wonder why mine have been exactly the same ever since I bought the Tweecer

Not that much!

More like .1 to 2.5% diff

It does vary :)

I've always thought its because I run all emmisions stuff :shrug:

I've seen other peeps say their's doesn't vary much at all.

Grady
 
zenboy99 said:
Huh, well all I did is change the intake, maybe I have a bad injector on one side?

When EEC analyzer calcs the MAF curve does it average the two banks to determine its reading?

The following is a guess on my part :)

From using an old Excell file in the past to help select the best inj values to use for CL conditions, I did see some averaging going on.

Most of the time, you see EA ask for pw1&2, lambse1&2, KAMRF1&2, etc, when dialing in various things and I do think it is to allow the average outcome to be used in selecting the final value.

Grady
 
So I just went for a drive at lunch, my left O2 was stuck at 0.05-0.07 volts and both Kam values read exactly the same. So maybe if one O2 isn't reading, it uses the other O2's reading for that bank?

I have my wideband sensor on the left side and thats reading normal, so maybe its a wiring issue? That O2 is brand new.
 
zenboy99 said:
So I just went for a drive at lunch, my left O2 was stuck at 0.05-0.07 volts and both Kam values read exactly the same. So maybe if one O2 isn't reading, it uses the other O2's reading for that bank?

I have my wideband sensor on the left side and thats reading normal, so maybe its a wiring issue? That O2 is brand new.

They both should be switching back & forth rapidly during CL driving conditions.

If the O2 is switching with lots of activity and its output is not all that different from the other, I don't think there is a prob. I base that upon what I've seen and other self tuners have told me they have seen.

btw, do you have a new bung for your wb or are you doing the wb narrow band substitute thing :shrug:

Grady
 
Still a rookie, but this didn't seem right to me

I have a somewhat related question I thought I could piggy back on this thread.

My PW1 & 2, LAMBSE1 & 2, and KAMRF1 & 2 are always the same or very close.

My HEGO1 & 2 can be very different. Some examples
-----1-----2
---.72----.48
--.026---.17
--.012---.002

Do these numbers seem reasonable, or should I start looking for bad O2s, wiring?

Thanks,
jason
 
WhiteDevil said:
Good question i plan to get a new bung welded in a little further down stream from my stocker. I wonder how that will work.

I have a bung in each collector of my LT's just a bit behind the narrow band O2's.

I asked Don if he liked my method or the replace one narrow band with the wide band method.

He said he prefered a seperate bung for the wb thus keeping the original O2's undisturbed.

btw ... I have switched sides with my wb and it seems to show no difference.

Grady
 
I have a seperate bung for my wideband on the drivers side in a different position from the O2 sensor.

Still haven't figured out the wiring for the O2 sensor. I've tried 3 different sensors and they were all the same. I'm thinking it my be in the cheap O2 wire extenders I got from BBK.