Has anyone had any problems on their 2005 Silverado with O2 sensors not being installed? I have a 2005 Silverado 2500HD 4X4 with 8.1L big block gas engine and 6 speed manual transmission. It has trailering package and snow plow prep package and camper package. Truck has GVR of 9200lbs. on door. It only has 2 O2 sensors above the catylitic convertors. This is all it had since it was brand new, and I am the only owner. Chevy dealership can not find wiring harness either to plug in replacements. They say it is suppose to have 4 sensors. Mechanic last night told me that he thinks it is because it is rated for >8600lbs. This is the first time this issue has come up in the 4 years that I have had this truck. The dealership told me yesterday that the truck can not be fixed!

 

These are the locations according to the book if its stock. Welcome to the forum!

 

This did not address the problem.

 

Well alrighty then, just trying to help.

 

What seems to be the problem with them though?? Your truck is not suppose to have them, the emissions equipment is different for that large of a truck than your typical setup.
If got a 04 gmc with 8.1/allison and i don't have them either. the exhaust bungs are capped and the truck doesn't need them.

 

OK, so now I have found someone else, and someone that supports my claims. The local Chevy dealership states that it MUST have 4. But I have argued with them that it only came with 2. They would not inspect it. The MOTOR 2009 manual that the state of NC uses says it only needs 2. I called and told my salesman, he called AAA Automark and got the "2 only" answer from them, adding that they have found the same problem in other customer Silverado trucks. Fast foward to yesterday, I obtained a vehicle build sheet and this is what it said: "FE9 federal emissions" as 1 order option, but then it also says on the same option order sheet in a different area: "NT9 emission system federal tier 2 phase out". Per a private Chevy mechanic, the NT9 option means that this vehicle pulls as much as the Allison diesel option and does not require the 4 sensors, even though Chevy will tell me it does until they are blue in the face! Is this the same info that you have?

 

Wel the only reason i know is that i was under the truck changing oil and i noticed it, talked to local mechanic about it and he said ya that is the way it should be, it has different emision system, so that is were i left it at,
What is your truck doing that you got to looking at it?

 

I have a similar issue with my truck but it was not a problem. I do not have EGR, since it bought it in Texas, I now live in california where its required and my smog guy said its not a big deal at worst its just a $10 fee when registering it. I never got charged anything because of it when I registered it. Its just they way its made to run for where they are sold in the country.

I just posted the pictures to show where they were, I misread your post.

 

After consulting an attorney, seeking info from a second dealership, writing to 2 different EPA agency's, writing to "Car Talk", several members of of GM coporate, 2 TV stations, and Ralph Nader org., I found out that this truck does NOT have California emissions. Which is rare compared to batch built trucks by Chevrolet. It is not even suppose to have emissions inspection, since it is over 8600lb. GVR. But it is what I have been telling the 1st dealership and customer service at GM all along.