Checking O2 sensor wiring
 

How do you check O2 sensor wiring to make sure it's not burnt or shorted? I recently got a P0151 trouble code and my car started to run bad. I also replaced my O2 sensors 150 miles ago.

Re: Checking O2 sensor wiring
 

A digital volt/ohmmeter is a handy little tool that can check electrical wiring and find circuitry faults. They can be found at just about any hardware store.

Re: Checking O2 sensor wiring
 

I have one but what voltage am I looking for and does the ignition have to be turned on?

Re: Checking O2 sensor wiring
 

If your meter has a continuity feature, you can use that to check the condition of the wires themselves. The ignition needs to be off though as the meter provides its own reference signal.

Re: Checking O2 sensor wiring
 

If I find the harness side of the wiring is burnt whats the best repair that can be made? Solder in a new pigtail? I'm pretty sure the wiring is the issue because I installed another O2 sensor and it had the same symptoms.

Re: Checking O2 sensor wiring
 

Ttt.

Re: Checking O2 sensor wiring
 

Yeah, definitely solder in a new pigtail if you can get one. Soldering is your best bet finished off by some heat shrink tubing to ensure a good, tight seal.

Re: Checking O2 sensor wiring
 

It been a long time since I had anytime to work on my car and I finally got to take a closer look at the passenger side wiring harness and found that my header had burned through the plastic tube containing a couple of wiring harnesses. It burned off some of the isulation on the passenger side O2 sensor wiring and CPS wiring. The CPS isn't an issue since it's programmed out. Since I didn't have a new O2 pigtail lying around I cleaned up some of the wiring, removed the burnt plastic and individually taped up all of the wires that were exposed. Some of the exposed wires on the O2 harness looked slightly oxidized and some of the strands were broken. I then wrapped everything up very well with some heat resistant tubing and tape. I fired it up and the car ran a little better but it backfired at low RPM like nobody's business. At higher RPM and WOT it ran fine with no backfiring. I took it for a short, 5 minute, test drive and it did not throw any codes. The code I had been getting was a "P0151"=Heated Oxygen Sensor (HO2S) circuit low voltage Bank 2 Sensor 1. From my description of my problem does it sound like I found the culprit and need a new O2 pigtail?

Re: Checking O2 sensor wiring
 

Anyone else burn up their O2 wiring and experience the same problems?

Re: Checking O2 sensor wiring
 

I just went through the EXACT same thing....do a search on my username to read the whole saga. I've spare you the details here but the end solution was to solder and heatshrink and extra 4 1/2 feet of wire in the middle of the harness, replacing the damaged sections, and reroute the harness down near the battery, to the K-Member, and beside the block rather than down the fender well next to the headers as it was from the factory. No matter how much heat tape / 1000 degree heat tubing I used, mine needed at least an inch or more clearance from the headers which was only possible by rerouting that section of the harness. Good Luck! Shoot me an email if you have trouble or any questions.....like I said I just went through the exact same thing myself.