Hey guys, I posted this over at the tunercats forum monodax.com also.
I was under the impression that changing the values in the stoich AFRvs % alcohol in fuel table would make NO difference to my vehicle: 2005 4.8L Tahoe NON FLEX FUEL.
The table makes sense if you have an alcohol % sensor. Well I changed the values, up to 12.5% to 14.37 and EFI Live reports the desired AFR as 14.37 MY WOT also reports richer in EFI Live (14.37/1.165).
What I'm asking is why would EQ1=14.37 if I dont have a flex fuel vehicle?
EVERY pump here in Atlanta says may contain up to 10% ethanol so I'm assuming its in 90% of the pumps. Unfortunately this is my wifes truck so I dont have a bung for the WBO2. How much will my reading be skewed when the sensor is 6" in the tail pipe? What about taking out the rear 02 and installing there?
Well I hooked up the WB and have some results. Can someone point me in the right direction with the data I have?
I commanded open loop and reset fuel trims via EFI live scanner(love it!)
Commanding 14.68, at idle WB reads .98L 02's average .560's mv's
Commanding 14.37, at idle WB reads .96L 02's average .560's mv also.

I FINALLY understand (found) the closed loop airflow mode! NOW the rich/lean 02 volts table makes sense. My gut tells me to raise/richen the mv to .550 across the board. Also, it appears to me by changing the value in the % ethanol table, I'm telling the PCM that EQ1=14.37. Is this true?