O2 VALUE _________________________________________________ (range not available) Indicates the operation and short term correction of the fuel delivery. It shows whether the ECM is commanding a rich or lean mixture. The number theoretically can range from 0.00 to 1.99 with 1.00 as the midpoint. A number above 1.0 indicates that the ECM has commanded a temporary rich mixture correction. A number below 1.0 indicates that the ECM has commanded a temporary lean mixture correction. These short term correction numbers are also used by the ECM to learn a fuel correction pattern or trend and are stored in the learned mixture or lambda values. Fuel correction operates only in closed loop. In open loop, a fixed value displays.