04 Yukon 8.1

[yukon25008.1]

im trying to do a tru 3" on this truck, and am not sure about these cats theres a sensor right after each one, can i eliminate them and not have a "check engine light"

[ATMINF]

These truck normally have 4 O2 sensors 2 before the CAT's and 2 after. The easiest way to "remove" the 2 after the CAT is get a tune with them being "turned off". That is what I had done as part of my tune. The 2 O2 sensors prior to the CAT are needed as they provide alot of information to the computer so the truck can run properly.

[yukon25008.1]

Ok, so its not a big deal, when i remove them before the tune what will i have to deal with? a check engine light i can deal with as long as it runs ok until the tune

[yukon25008.1]

?????

[hockeypro1411]

Yes, it should run fine. But the CEL will stay on until you get a tune to get rid of it.

[Z'06]

Yes, it should run fine. But the CEL will stay on until you get a tune to get rid of it.

 

+1, just like after gutting the cats. If the light bugs you or you need to pass visual inspection before you get it tuned, you could look into getting some cheap spark plug defoulers (effectively spacers) that lift the rear O2 sensors just out of the pipe to where they won't report a problem.

[ATMINF]

The truck will throw a code, and check engine light will come on. I am not sure what the long term effects it will have with the code being stored in the PCM. I have heard many different things about having a check engine light stay on and how it effects the car, ie: will it go into a "limp home" mode etc..?? Since I am not a tuner or programmer I really don't know. I just know that if the light stays on, there lies a possiblity that another engine/trans problem may come up, but since your check engine light is already on you may not know of the "new" problem. For me I would just tell you to get the tune, and get it done. Most of the tuners have no issues with giving you updates to their tuned PCM for free. I know with my Wheatley tune, I can always send my PCM back and get it retuned for larger tires, or change it from a 87 octane to a 92 octane tune. Hopefully this helps.

[yukon25008.1]

thanks alot guys. i wish i knew more about the :spark plug defoulers" do they just take the place of the o2 sensor?

[Z'06]

thanks alot guys. i wish i knew more about the :spark plug defoulers" do they just take the place of the o2 sensor?

 

I found this picture on Google images. That shinier part on the right side of the O2 sensor is a spark plug defouler. It is nothing more than a spacer - you thread your O2 sensor into it, and then re-install back into your rear O2 sensor holes. Piece of cake, and just a few dollars at your local auto parts store and a few minutes of your time.

 

[yukon25008.1]

thank you so much, and that little spacer will keep the CEL from coming on?

[yukon25008.1]

talked with auto parts store today about the defoulers, theyhave some there but.. the sparkplug thread is 14mm and the 02 sensor is 18mm so how can i get this to work

[yukon25008.1]

?? 14mm 18mm ??