O2 windows, specifically on the 16197427 $0D

[FSJ Guy]

Ok, so we got talking about O2 windows and then started hijacking another thread! :D

New thread time!

I found 4 tables for O2 windows:

Closed Loop @ 0x48F5
Open Loop @ 0x48F7
Closed Loop Idle @ 0x48F9
Open Loop Idle @ 48FB

The limits are all DIFFERENT! Some, not by much, however. The upper limits range from 677mV to 734 mV. The lower limits are from 278mV to 352 mV.

How much should I tighten them up to? Or, in what increments do you suggest I change them? I, too, think that swinging the AFR up and down is pretty silly. Seems like the motor would be happier with a constant AFR, not something that's zigzagging all over the place.

Thank you!

[gregs78cam]

I, too, think that swinging the AFR up and down is pretty silly. Seems like the motor would be happier with a constant AFR, not something that's zigzagging all over the place.

The thing is that the NBO2 is only accurate in a narrow band right around stoich. Hence the name. So the best signal the PCM could possibly have is one that goes rich to lean to rich just as fast as possible.

And here are a few more.

493D O2 mV Hysteresis for Rich/Lean
493E Minimum Slow O2 Error to Update INT
4940 Rich Idle O2 Voltage Threshold
4941 Lean Idle O2 Voltage Threshold
4942 Mean Rich/ Lean Idle O2 Voltage Threshold
4943 Proportional Duration Offset at Idle
4944 Proportional Duration Dead Band

The Idle PID parameters follow next.

Then a few more tables that deal with O2 and airflow starting at 4CD7.

[JeepsAndGuns]

Yea watching my innovate WB gauge while idleing, its jumping up and down a lot, never steady. I have been meaning to take a video of that thing and post it.

[PJG1173]

my WB and NB did the same thing at idle I reduced the idle spark error correction and that cut the bouncing around down alot. still swings all over the place while driving though.

[EagleMark]

There's a good read in the writeups on O2 sensors. It shows a bench test with volt meter and a propane tourch. Mentions readings as being lead fouled or silacone fouled as well.
http://www.gearhead-efi.com/Fuel-Inj...-on-O2-sensors

[FSJ Guy]

And here are a few more.

493D O2 mV Hysteresis for Rich/Lean
493E Minimum Slow O2 Error to Update INT
4940 Rich Idle O2 Voltage Threshold
4941 Lean Idle O2 Voltage Threshold
4942 Mean Rich/ Lean Idle O2 Voltage Threshold
4943 Proportional Duration Offset at Idle
4944 Proportional Duration Dead Band

The Idle PID parameters follow next.

Then a few more tables that deal with O2 and airflow starting at 4CD7.

I can understand the window tables. But what about the above parameters?

IIRC, the value for the Hysteresis for Rich/Lean was set at zero.

[PJG1173]

4940 Rich Idle O2 Voltage Threshold
4941 Lean Idle O2 Voltage Threshold

I've read on FSC.com about these can be used to adjust what afr the ecm thinks it seeing.

[RobertISaar]

I've read on FSC.com about these can be used to adjust what afr the ecm thinks it seeing.

you can use them to essentially change the target O2 mV where the ECM considers the rich/lean transition to be, i.e. Stoich.

some masks don't use single values though and use tables based on airflow/etc.

[EagleMark]

This brings up another parameter I have never changed. Stoich AFR! It's always set to 14.7 so if you changed it to 13.0 would O2 sesnor settings keep it there?

[PJG1173]

you can use them to essentially change the target O2 mV where the ECM considers the rich/lean transition to be, i.e. Stoich.

some masks don't use single values though and use tables based on airflow/etc.

yeah thats what the article said i just couldn't get my fingers to type what I was thinking. What I'm thinking is I can use these tables to basically recalibrate the O2 to compensate for the long tube hedders, or was I reading that article wrong?