The AFR+ system is an AFR gauge first and can be used to diagnose problems with your vehicle. At times you will need to enter the diagnostic mode to understand how your vehicle is operating. If your AFR+ system is programmed to enable closed loop operation in any of the programming modes then it is NOT possible to use the system for diagnostic purposes. Diagnostic mode turns off the closed loop modes so you can view the true AFR values of your vehicle during operation.
ENTERING DIAGNOSTIC MODE:
Be sure to record all your mode settings before changing any of the modes.
Move all OPEN-LOOP fueling modes to a value of 13 (straight up and down). This is a 0% fueling change.
Move all SWITCH-POINT modes all the way to the right by pressing the (->) button.
For most applications you should now only see a GREEN LED during any driving condition.