Recently I've had a CEL so I took it to Autozone and they said it was throwing a oxygen sensor code. I checked both the upstream and downstream sensors with OHM meter and they both show infinite resistance. I also checked the pigtail coming from the harness on the upsteam and it is showing 12 volts. There is two white wires and one black wire on both sensors. The two same-color coded wires (white) are the ones I had checked with my multimeter. Can a bad knock sensor be throwing a 02 code?

What was the actual code?

There are a half dozen O2 sensor codes for that year.

Gee that's a mystery? The counter person who pulled the codes never told me that. Didn't bother to show me the screen on the OBD II scan tool either. She just said "oxygen sensor" and that was about all I got. Rodney Dangerfield could have got more info from her....??  I think I'll just buy my own scan tool.

Ugh. Did she turn out the light? If not, go somewhere else and get it read again, and get the code.

 

I think everyone should get their own code reader. Even if all it does is read the code, it's an invaluable tool when you don't have to deal with the parts store person trying to sell you parts that you may(not) need.

Something that can read live data is even better once you learn how to interpret what the scanner is telling you.

Got myself a good OBDII scan tool. It's throwing a PO130 (upstream sensor). Great scanner. It even tells me which 02 sensor was bad. I removed that sensor today and put it back in just for practice.

If you erase the code does it come back right away?

 

I always try to check in the connector for dirt/corrosion to rule out a poor connection. Also make sure none of the sensor wiring is chafed/cut.

 

If that checks out, sensor's probably kaput.

where is this sensor?  got a pic?

Sticks out of the top left side of the front cat. Kind of points toward the Inner cv joint on that side.

The 02 wires look good all the way to the connector plug-in. The tip of the sensor had a baked-on light tan colored coating like it had been in a industrial oven. The code has been coming back after about one hour of driving. CEL illuminates after a driving cycle is completed.  

where is this sensor?  got a pic?

Sorry I forgot to take pics. I'll take some when I put a new sensor in it.

Edited June 12, 201510 yr by darsdoug

Found myself a good upstream 02 sensor today at the local boneyard. It did the trick. No more CEL and scan tool is giving the green light. I had to do a little splice job because someone had cut the pigtail off, but it's working great.