Help needed! How to setup and log Lambda error for flex fuel

[DRTWRK]

Been tuning my personal vehicles for some time. Thought I had this figured out years ago but when you don't perform same task frequently at least for me (Very Old and brain waves not switching correctly) becomes real pain in but.
I know this has to be much easier. I believe I'm over thinking but cant seem to be able log Lambda error.

Now I'm upside down in the whole PID, sensor, function relationship . Have Auto Meter WB02 and have been logging AFR Error for a long time.
Currently switching to flex fuel with DSteck's sensor and cant seem to get the correct formula to input into Tables, Histo's, etc.

I know this site is for learning and getting a straight/direct answer sometimes is more than difficult. Can someone make this easier as I've exhausted my search ability and found several examples but none related to flex fuel using the Stoich table that constantly change with Ethanol/Alcohol percentage. Is what I'm asking for possible with the varying Stoich?

[DSteck]

What's the output range of your wideband's signal? Is your wideband already logging in lambda? If so, just create a custom PID comparing the wideband lambda against Commanded EQ Ratio.

[DRTWRK]

What's the output range of your wideband's signal? Is your wideband already logging in lambda? If so, just create a custom PID comparing the wideband lambda against Commanded EQ Ratio.

Auto Meter is 4 volt. Yes I can switch it to read Lambda. My problem is creating custom PID's, Histo's etc. I get so frustrated at something probably so easy being so hard for me now.
I have input Commanded EQ Ratio (SAE) in main table and already had Air Fuel Ratio High Resolution. If I ever get this right will the WB02 reading Lambda follow the Stoich at the varying percentage of ethanol? Same question for the Lambda Error?

[DSteck]

Lambda is lambda is lambda. That's the first concept to understand. Lambda is a ratio off of stoich, and that's what wideband actually read. Throw the concept of AFR out the window.

Post the min and max voltage and the fueling range of your wideband. I'll tell you how to make it log in lambda in hpt. What you display on the Autometer is meaningless.

[DRTWRK]

What's the output range of your wideband's signal? Is your wideband already logging in lambda? If so, just create a custom PID comparing the wideband lambda against Commanded EQ Ratio.

Auto Meter Elite-0-4 volt
I checked the min/max as set and read 0V=0.68 and 4V= 1.09 lambda
I subtracted .68 from 1.09 = 0.41 then 4V/0.41= 9.756 and placed this number in my wideband under volts and set offset to .68
Although I think the auto meter guide appears to allow min/max adjustment I have not dove off into that yet.
I think I have my scanner logging Lambda now and it seems to correspond to my Wide Band gauge reading.
I have my flex sensor installed but have not ran any ethanol so I am still reading 14.68 Stoich as I still need to tune my VE with the new ID1300.
Heavy rains today prevented VE tuning. Getting my Lambda Error Histo is kicking my butt and seriously thinking about hitting the bottle and having my first drink in years.
I attempted to make custom histo and tried function 100*((([AUX.20124]-[PID.68])/[PID.68]) and several other variants 100*([AUX.20124-SENS.121])*SENS.121
with NO success. I am lost!
Any help you offer is greatly appreciated
Just kidding about the bottle

[DRTWRK]

Bump to top.
I still can use a little help on how to setup Lambda Error histo.
I have Lambda logging on my wide band and also reading in scanner.

[FunkedOut]

I agree; you should have a crack at the bottle.

Assuming your WB is logging lambda correctly as AUX.20124...
Assuming you're tuning your 5th gen camaro...

(([AUX.20124]/[PID.68])*100)-100 will give you error histograms you can copy and then paste special % (half).

Even though PID.68 is listed as Commanded EQ Ratio, on the 5th gen camaro, it is really Commanded Lambda.
I don't know why and I don't know what other vehicles may be this way.
Log it along side Air Fuel Ratio Commanded Hi Res ([PID.6001]), compare and you will see it.

[schpenxel]

Yes. Setup a PID for lambda error. It is basically (wideband_lambda / commanded lambda) * 100 - 100 will give you the same format as fuel trims are usually in

Commanded lambda = commanded eq ratio for most (E40's are weird and are inverse of that but forget about that) so you can just use that directly

Then just use that PID against whatever histogram you want. here's mine for wideband error vs. regular VE and boost VE.

Lambda ERror.JPG

Histo 1.JPG

Histo 2.JPG

[DRTWRK]

Thank you guys for your help. The screenshots and providing the correct function formula was very helpful.

Now I will get on with the rat killing in learning how to tune for flex fuel.