My friend who own a mitsu engine with its O2 sensor connect to apexi timer get a very low reading on O2 voltage,0.07 to 0.18volt only.last time it was fine can get normal reading.
sensor already change to another unit but still the same scenario.
the O2 sensor is a 2 wire unit.(blue/white)
i measure the voltage direct from the sensor both wire and get 0.1v same as what shown in the timer.Then i measure with a multimeter,the signal wire (+)and the chasis(-) ground then i get 0.45v...