Commanded EQ Ratio

Hello Everyone!

I am having trouble figuring out what (in this case COBB) is reporting as a commanded EQ ratio. This is on a Ford Ecoboost ECU. I see the target AFR mirror exactly what I input into my request tables, but this value seems to have a mind of its own. It will command richer/leaner than Stoich at cruise, and kinda just move around all over.

I attached some screenshots from a log, the first one is a 1-2-3 gear accel and then cruise, the second shows idling. It seems to go lean/richer than true target - I am unsure if I should even be paying attention to this when looking at fuel trims, as my actual AFR seems to be tracking my targets and not the Commanded EQ ratio - reading the documentation for this monitor it would seem that the EQ Ratio is the true target the ECU is requesting but it doesn't appear to be the case in my logs.

Andre talked about EQ ratio a bit in one of the lessons, and if I recall correctly that was more of a target vs actual ratio?

Any input would be appreciated!

Thanks!

I would ignore it. Commanded equivalence ratio (whetner its a Ford or whatever) on a stock ECU is usually the SAE j1979 PID meant for generic scan tools. It's not necessarily calculated the same and isn't for internal use. https://en.m.wikipedia.org/wiki/OBD-II_PIDs number 44 hex

Interesting thanks. I am going to get some clarification (if I can) on why they call it out as an important monitor to watch when adjusting SD tables for fuel trims in their docs, maybe its a typo, or no longer relevant. I will report back with what I find in case someone else can make use of the info as well :)