Got the P0031 code. Bought a new O2 sensor, no big deal changed them before. I have two long nose needle nose pliers and the ox sensor socket. I could not get the connector to release. Finally the worst thing happened, pulled all of the wires out of the plug. Could not find any info on the web, as to which wire goes where. I cut into the connector found some metal to solder to soldered in four six-inch lengths of wire. Had to drop the exhaust pipes and pull the driver side cat. The nuts on the cat have an end that is deformed, so they have a locking effect. They tend to damage the studs when removed. Had to tap out the nuts to get them to go back on smoothly. Ran them on and off a few times with the impact wrench until I could turn them by finger. I'm getting a little ahead of my story.
I got the four wires soldered on the connector and the harness. OH the joy of solder ***** bouncing off my face mask and on to my neck to cool and congell I have the connector secured to the harness and no idea which wires of the sensor go where.
This should not be too difficult, just ohm out the sensor. Two wires have 15 ohms and other two have no continuity to anywhere. I turn on the ignition and I have 12v. or B+ same thing going to another pin must be htr or heater return. I figure, I got it mostly figured out. I cut the wires on the sensor and soldered them to make the heater circuit. All I have the do is swap the other two wires if the computer throws another code. I got a new code, something about no signal. I have to have a book.
After looking at a few sites, I decided to take a chance on Chilton. I have had Chilton books before. The schematimic always look like a copy of a copy of a copy and so on. I spring for the $16. I was trully surprised, The schematics are great. Thats where I found my big mistake. I had the heater running to ground. The circuit has a transistor controlling the return. Thank you schematic.
Here is how I figured things out. I took the old sensor and soldered on lengths of wire that would reach to the ECU and labeled them. I found the four wires in the circuit. I pushed straight pins into the connectors on the ECU to ohm out the circuit. I moved a couple wires on the sensor. All is good now.
A tip: If you will be connecting and disconnecting your sensor a lot, cut the nib off of the sensor and use hot glue, rtv or goop to hold it together when done.
This took weeks to cure. During this time my radar and regular cruise went bonkers. They both work normally now.