O2 Feedback Box - Power FC

The setting here relates to the INJ map. Any cell with an INJ value below the setting value will be subject to O2 feedback/correction provided the function is turned on.

Before I showed how most people use the INJ map, for fuel adjustments, and then ReCelc Base and set all the values back to 1.000. As you can see, this will make every cell in the map subject of O2 Feedback Control if the function is on and the default setting value is used.

You need to pick the setting value so that you are only applying O2 feedback correction to cells very near stoichiometric. I use a value of 1.035, which corresponds to a commanded AFR of 14.2:1 (assuming 14.7:1 as base AFR value).
This would work well when using the INJ map as a target AFR table.

However, in practice this function works extremely poorly. It is very slow to respond and wildly overshoots stoichiometric.

I find that at idle, the car will fluctuate between 12.5 and 16.5 AFR with this setting turned on. Unfortunately, the settings that control the response of this function are protected and hidden on the Power FC.

On more advanced ECU's such as the AEM EMS, these functions are tunable.

Since the function essentially doesn't work, I just leave it off permanently. With the function off, you no longer have a real consideration with how you use your INJ map.