How to determine if wiring harness connector to 02 sensor is bad???

Moco

Member
Nov 10, 2002
35
0
6
Arlington VA
OK Guys,

I need some input here, but please try to follow along with a little bit of history for this problem... I kept getting a P0141 heating circuit malfunction (bank1 sensor 2) and P0174 (bank 2 lean). Anyway, I recently got new header gaskets replaced (as well as h-pipe to header gaskets) and the P0174 seems to have gone away (knock on wood). But the P0141 still pops up regularly about every couple of days or so. Now, I know its most likely not the 02 sensor because I replaced all 4 last year. So yesterday I decided to take a look underneath the car to see what I could find... well the MIL eliminator (for bank 1 sensor 2 [passenger side rear]) was battered and looks like a portion of it had MELTED on to the wiring harness connector. I managed to seperate the MIL eliminator from the connector and used some electrical tape to tape up some of the wiring that leads to the broken plastic on the connector. For good measure I swapped MIL eliminators to see if the battered MIL eliminator was causing the P0141 code. After connecting everything up and running the car for awhile, I've started getting P0136 and P0141.

Now the P0136 popping up ensures that the MIL eliminator is bad. But the continued presence of the P0141 leads me to believe the wiring harness connector to the 02 sensor has a short or damaged wiring (assuming the 02 sensor itself is good - which I think it is).

My question is: how can I test the wiring to the connector to determine if it is bad and if it is bad how do I fix it? Please keep in mind, I know next to nothing about splicing wires or wiring in general and I have no access to a lift. I dont have to replace the whole wiring harness do I??? If anyone has any suggestions, please give detailed instructions, as I am a wiring novice. Any help would be appreciated because I really want to get rid of this annoying CEL.

Thanks.
 
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I would start off by just taking a good look at the entire harness, from top to bottom, and see if you are overlooking something obvious, such as a cut, or melt in the harness somewhere. Check the pins on the actual connector itself, and make sure they all appear to be sticking out the same amount. On the female side of the connector, make sure there's nothing blocking any of the holes where the pins would be inserted. That's an easy place to start.. after that you'd want to check the factory service manual for voltage values, and pick up a digital multimeter, and check each wire.

Replacing the whole harness wouldn't be that hard if need be.