Mode II (Exhaust Gas Monitor)

In Mode II, both Red and Green LED's are used to monitor air/fuel mixture feedback control. Green LED will function the same as in Mode I. In open loop, Red LED will remain on or off along with Green LED so vehicle must be in closed loop in order for Mode II results to be valid. In closed loop, Red LED will indicate if system is running rich (light off), lean (light on) or if at the ideal air/fuel ratio (blinking synchronized with Green LED).