Missing O2 Sensors

[orhuntnfish]

Well this is a new one to me. I got the part numbers from the dealer for all 4 O2 Sensors. I have a 2002 Yukon XL SLT 8.1L 4X4. The dealership and All Data both say there are 4 sensors. But there are only 2. The ones there are both upstream. The ports on the exhaust for down stream are plugged and there are no connections electrically. Also there are only 2 fuses for them, Any ideas why this might be?

 

[Doubeleive]

Well this is a new one to me. I got the part numbers from the dealer for all 4 O2 Sensors. I have a 2002 Yukon XL SLT 8.1L 4X4. The dealership and All Data both say there are 4 sensors. But there are only 2. The ones there are both upstream. The ports on the exhaust for down stream are plugged and there are no connections electrically. Also there are only 2 fuses for them, Any ideas why this might be?

a previous owner probably deleted them and tuned them out.

 

[orhuntnfish]

I wonder why someone would do that. Kind of weird.

 

[drakon543]

I wonder why someone would do that. Kind of weird.

likely possibility that the cats are punched out or they were having issues and had them tuned out. or someone had other toys on it and when everything was put back to stock for a sale they left the tune so the o2 sensors didn't need to be put back in.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

You are already receiving suggestions and perspectives from the great folks here.

Pics, please.

 

[the_tool_man]

+1. They were tuned out and never replaced. When I got my 2012 BB tuned, he offered to turn them off. This gives me the flexibility to delete them later if I want, without another tune. The only downside is that I have no way to know when my cats go bad.

 

[Rocket Man]

I had my downstream ones tuned out when I installed longtubes. I’m running a wide and sensor in the DS location because supercharger.