How do I use mode II on the ECU to determine if engine is running rich, lean or normal? The FSM says nothing about how to enter mode II. I know I wait for 2 flashes, turn ECU back to normal to enter mode II. It says nothing about running the vehicle and I'd imagine the car would need to be running for an accurate reading.

 

In mode two your car will use the sensors(O2 and such) to measure A/F ratio. If you too rich the red light will blink. If you just about right they both blink at the same time. If its lean then the green one will blink.