2008, v8, 4x4, stock save for a K&N
So, at 215k my truck popped its first emissions error codes. P0038 and P0138. Unfortunately, when I Google these I get ten millions hits, and they all are either contradictory or for a different car. I have learned that Bosch is no bueno for dodge, which is ok, the NGK is cheaper.
What I am struggling with is the contradictory parts info. I think that I might have 3 o2 sensors, and that some places list the upstream and downstream as the same part, others differentiate up and downstream. I also don't know if I should just replace a bad one or all of them on general principles.

Basically, I don't know what to buy. Since I was planning on buying on the net, I am scared of finding out what I bought is wrong while I am under the truck. So, if y'all could point me in the right direction, I would be grateful.

 

That's whining about the rear O2 sensor. It's likely just internally shorted, it is pretty old, after all. My local Advance Auto will price match Rock Auto for me...... getting it locally avoids of lot of the issues of getting the wrong part. Sometimes, buying locally is cheaper, as you don't have to pay shipping either.

 

I had one upstream sensor that went bad, I replaced them both with OEM sensors.


O2 sensor, Both Upstream & Downstream right, part number -->