School me on O2 switchpoints

[ddnspider]

0049 is with 450mV switchpoints, 0051 is with 370mV switchpoints.

Interesting logs that your LTFT's are basically the same even with the switchpoint change.

[maudyZ28]

i need to have a look at those logs.

maybe test really low switch points about 300 mv ?

Do you verify AFR with a WB or just based upon LTFT...?

[ferocity02]

i need to have a look at those logs.

maybe test really low switch points about 300 mv ?

Do you verify AFR with a WB or just based upon LTFT...?

I used a WB in those logs, however I do not entirely trust it. I got an AEM wideband instead but haven't had time to try it again.

[maudyZ28]

doesnt appear to be a massive change but the average NB are reading lower, but only about 380 mv when SP are 370 and they read at 430 mv when SP are 450.
WB doesnt change mych either.

Also , I dont like how your NB are switching, they seem very choppy. Maybe its just me but mine are all nice and smooth up and down occilations, not jumpy. But I have headers now too...

[EagleMark]

Changing this entire B4105 table is just changing the switch point where the cross count occurs, noted as Initial Value in picture. Without the Lean and Rich or High and Low parameters it's not an effective tool for tuning AFR.

If I lower my entire table down to .200 range it will change Lambda from about .97 to .99. But can get a lot lower AFR by raising them to about .95 Lambda.

This is dependent on the O2 sensors which vary.

In a tune running Open Loop and using Lambda readings from Wide Band it was a steady 1.0

Go closed loop and let Narrow Bands do the adjustment and here's what I got from various O2 sensors.

Closed loop:
Bosch O2 sensors = .98
Second set of Bocsh O2 sensors = .99
AC Delco O2 sensors = 1.02
Denso O2 senor = .99

My real thought was AC/Delco O2 sensors are set lean to Stoich for MPG ratings?

Now if you had the Lean/Rich setting it works real well, also tightens up the swing you see in data dash. See pic...

I've been looking at all these settings trying to find a rhyme or reason in the way GM did these and there is none? Been changing them for years with excellent results shown in WB. Just recently was told by factory engineer the reason I could never find how/why/what? Was they are all just tweaked to whatever works best with the CAT for gas analyzer, has nothing to do with the AFR or way engine runs, although it will, at that point they don't care and it has to work with the design of the CAT and pass emissions for that YMM.

[Highlander]

That appears to be a tunerpro file.... care to share that xdf?