Hi, i just replaced my o2 sensor in my 90 3.0 4runner but the cel will not turn off. I checked the voltage and it is way too low. I think that is indicating a lean engine or a vacuum leak. Nothing i do changes the voltage nor could i locate any vacuum leaks. How do i get it in the right voltage range?


thanks matt

 

What voltage are you measuring and how are you measuring it? I use an analog volt meter and note that there are ~8 voltage changes in 10 seconds from ~0.2 volts to 0.8 volts. A digital meter may not show the rapid voltage changes, but you can watch the needle "twitching" on an analog meter. Or now, I have an Air/Fuel meter connected and just watch that while driving.