[joshsill]

Sorry if this has been asked but I couldn't find anything while searching. Where are all of the O2 sensors located? I could only find one upstream (aren't there two?) in the service manual located on the exhaust manifold. What is the best procedure for testing them to be sure they are working correctly? I have seen some stuff about warming them up on the engine and checking the voltages but I'm still a little lost on how to do this.

Thanks,
Josh

 

[TwoBills]

There's 4 sensors. 2 before and 2 after the cats. Generally, you warm up the truck, put a meter on a sensor, at idle, and take a reading. S/b something like .5vdc. Run the revs up to about 2500rpm. You should see the voltage run up to 1vdc, or so. This is a good sensor. A bad sensor will read low or zero and won't react to the rpm change.

 

[SouthernAppal]

Useful info is on this thread

http://www.clubfrontier.org/forums/f46/oxygen-sensors-54500/