Low volt reference to o2 sensor renix

[8Mud]

I did have a similar problem in my 98 sport, about .8 volts reference to all sensors, turned out my alternator had almost died, my jeep seemed like it was missing w cylinders, misfired, died easily, replaced although and all cleared up

Good idea. Try switching your meter to AC and see what you get, some meters will read a bad alternator diode as AC current some won't. Worth a try.

 

[DaveXJCO]

That's a good point!!! When the tester I'm using is brand spanking new to me. Actually its a test light with a volt meter built in. It is designed in just finding 12 volts probably. Interesting. I haven't even checked the o2s function yet because I assumed an issue. And my harness seems to be super clean as well. Hmmm. Wish I had an analog meter to check what the o2 is sweeping at. Its time for a new one mileage wise. And I also was running rich this winger due to a bad ect sensor. That could have fouled out my o2 sensor. Basically. I'm trying to figure out why the idle fluctuates when cold but is fine when its warmed up.

 

[DaveXJCO]

Thanks for that info regarding using the proper tester for a low volt circuit. With the right tool I am indeed getting the proper voltage to my o2. So that circuit is OK. Replacing the o2 sensor tomorrow as it is time for a replacement mileage wise. Then off to emissions. I have to say. The installation of a nerwer ecm has definitely made my keep run smoother. Or crisp if you will. Acceleration feels smoother. Throttle response its quicker and also smoother. I feel more power at lower rpms when I up shift. I'd recommend anyone with an 87 get an 88-90 ecm. Its like having a tuner installed.