Below is the data captured on my test of the O2 output signal at idle and 2K RPM.
At idle (800 RPM):
With hho 0.6v to 1.25v o2 sensor output signal, and most of the time the range is 0.7v to 0.8v.
While without hho 0.6v to 1.25v o2 sensor output signal, and most of the time the range is 0.9 to 1.1v.
At 2K RPM:
No noticeable difference on the O2 sensor's output signal.
Based on the data mentioned above, we can conclude that the ECU will send a signal to the fuel injectors to increase the output since it detected that the engine is running lean with HHO.
My next project is to add an EFIE to control the O2 sensor's output signal to maximize fuel efficiency.
