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Eric, Automotive Repair Shop Manager
Category: Chevy
Satisfied Customers: 30828
Experience:  20+ yrs. experience as repair shop manager and technician.
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2005 chevrolet cobalt: oxygen sensor..the wires are different colors

Customer Question

what are the color on a 2005 chevrolet cobalt oxygen sensor? I am trying to replace the stock one with a universal one but the wires are different colors. How do I know which is which?
Submitted: 7 years ago.
Category: Chevy
Expert:  Eric replied 7 years ago.



Couple of quick questions so that I can pull up the correct wiring diagrams and colors.


Are you replacing the upstream or downstream O2 sensor(before or after the catalytic convertor)?


Which engine size - 2.0L or 2.2L ?

Customer: replied 7 years ago.
this one is supposed to replace both it is in the back of the manafold and it is the 2.2
Expert:  Eric replied 7 years ago.



Ok, below is wiring diagram that gives both wire colors and what they go to:




connector views with same information, plus pin number:



Customer: replied 7 years ago.
ok, the colors that are on the factory one are one blue one white and two black... on these diagrams none of the colors are blue....that is the trouble that I am having. I dont know what the colors are on the one that came out of my car.
Expert:  Eric replied 7 years ago.



are you referring to the wires at the o2 sensor, or the wires on the wiring harness ?


The wiring schematic I provided shows the wiring colors on the harness side, not the O2 side, which is what you need to know-the harness side. it doesnt matter what the colors are on the original O2 sensor. it only matters what the wiring color is and what they go to on the harness side.


can you get me the 17digit VIN code and I can double check the diagrams from it.

Customer: replied 7 years ago.
Expert:  Eric replied 7 years ago.



what are the colors of the wiring on the harness side-this is the wiring that goes to the pcm, not the pigtail wiring harness off the o2 sensor itelf/







Customer: replied 7 years ago.
I need to know, which wires are the heater wires, the lead wire, and the ground from the diagram that you sent.The wires on the factory o2 sensor are two blacks, 1 blue, and a white. On the universal one I bought it says there should be 2 heaters, 1 lead, and optional ground. And on the universal there are 2 whites, a black and a gray. Which goes to what
Expert:  Eric replied 7 years ago.



I am going to opt out as it doesnt seem you are able to read schematics. another expert will be with you shortly.


please dont reply to this as it will lock the question back to me and no other expert will be able to help you

Customer: replied 7 years ago.
if i am asking you then appreantly i dont know how to read schematics. You dont have to worry about getting any other person to help me I will figure it out on my own. And next time you shouldnt be so damn rude. If I knew what I was doing I wouldnt be paying you to answer my question.