Where are the 02 sensors located and what is the installation process?

TROYSR10

MEMBER
2009 CHEVROLET SUBURBAN
5.3L
V8
AUTOMATIC
150,000 MILES

I have a brand-new cat and before I go and have it installed I don't want to be charge more money to put 02 sensors on. So, i'm thinking that I can put the new 02 sensors on the new cat before I go an hv my new cat installed, but the question is, where do they go and how I put on?

1 Reply

BRENDON S

MECHANIC
653 POSTS

Good morning, TROYSR10,

I have added some images of their location. Using an Oxygen Sensor socket is the best way. I have added a couple of images of some that would be a good choice.

Another way is to use an open-end wrench. I do not recommend this. It can work for install but if the pipe is installed in the vehicle, it will be a lot easier with the O2 Socket and a 22-inch 1/2'' drive ratchet.

The new O2 sensor should be handled like a piece of china. Do not allow the tip to touch anything as it may become contaminated. Apply a small amount of anti-seize to the threads and hand-tighten the sensor in the exhaust bung, being careful to keep the tip away from the sides.

It may also be necessary to run a thread chaser or use a tap and die set through the bung before you try putting the new ones in because sometimes the threads are rough and need to be cleaned up, so the new sensor goes in smoothly. This is assuming you bought the whole "Y" pipe brand new.

If this is the case, putting the new ones in might make it more difficult to put the new pipe on as they will more than likely be in the way. If they have to take them off, they are just going to charge you for taking them out and putting them in.

If they are cutting out the old cats and welding new ones on the "Y" pipe, then you will need a torch to heat the bung up to get them out of the pipe. You want to only try to heat the pipe bung, so it expands away from the oxygen sensor. Then hope it didn't take the threads with it. Using some PB Blaster will help in removal especially if you put it on the night before. I would not use an open-end wrench in this case, you will just strip it. For removal of old ones, you will need the Oxygen Sensor socket. You will also need to tap the threads before the new ones go in.

Here is a link to an article that may help you as well:

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

I hope this helps. If you need any more help just reply back.

Thank you,
Brendon

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