RomRaider

Does anyone understand exactly what AF learning #1, AF Correction #1 and AF Correction #3 mean, and how they intereact with eachother? If you could take a second to explaine it to me that would be great!

A/F correction #1 is used only in closed loop and shows you the amount of fuel immediately added or substracted as measured by the front O2 sensor to achieve the AFR listed in your main fuel table at a particular load/rpm(which is always 14.7 on pretty much all maps I've seen, tuner or otherwise). Its value will go to zero when you hit open loop.

As the ECU notices consistent trends in adding/removing fuel at certain from A/F correction, it will make these changes more permanent and apply it to both closed loop and open loop (A/F learning). The reason it applies it to open loop is that the ECU has no idea whether it is hitting its AFR targets in open loop, so it assumes that if the car is running lean, for example, consistently in closed loop, then whatever issue the car is having also is affecting open loop fueling.

A/F correction #3 is the immediate correction to closed loop fueling based on input from the rear O2 sensor, which monitors the downpipe cat's performance. Rich is bad for emissions and cats, so its purpose is to primarily lean out the closed loop AFRs (over a small range of authority) to achieve maximum cat performace (which is usually at 14.7 AFR).

Thanks!