wide band 02 closed loop control:

In simple terms, closed loop control takes air/fuel ratio measurements form the exhaust mounted Bosch wide band sensor (very high rate highly accurate), this data is analyzed by the PC5/auto tune and adjust the fuel delivery to the injectors real time all the time based on the air/fuel ratio you select in the PC5....

narrow band lambda sensors do NOT have the sample rate and accuracy to gather data fast enough to feed back changes to air/fuel in real time

I run 13:1 AFR

turbo or supercharged motors need 12 to 12.5:1 AFR for gasoline, alcohol motors run 6:1 AFR

this guy does a half way good job of explaining it