Just an update, The Spartan has a feature where it sends a voltage value of 1.66 then 3.33 volts on startup. I did a very short datalog and the AFR value is correct with the equation as is.

The quality of the part is outstanding. Shipping was very slow however and the website flagged my debit card when I tried to order. It sounds like its a small operation however and they are very...

I must not have searched for the right thing. That thread was very helpful.

I just purchased and installed a Spartan 2 WB02. Previously I was use an AEM UEGO that I was borrowing from a friend. I am not sure how the AFR value is actually calculated for logging in the ADX? I...