Update: I was under the truck and there are only two sensors up and down. So that question is answered. Did another auto parts store checking to see what they have and nobody is carrying Denso or NTK( they are out of stock everywhere) NAPA which only has access to Denso. The only other brand available in the other stores are Walker. I have never heard of them. Anybody hear of that brand?

 

The NTK O2 sensor part numbers for your truck are as follows:
Upstream 23506 or 23151 - 1st sensor has a 12" long connector and the other has an 18" long connector - (measure the length of your wire/connector to determine which one you need)
Downstream 23099

With those part numbers, I'd check eBay and all other auto parts stores.

 

They did get one of them in today for the upstream Denso. The other one will come in Tuesday so if this isn't the right one ( thinking length in wire) then I can swap them out. I got up there and soaked the crap out of it with PB Blaster. Will let it sit over night and try to remove it in the morning. Thanks for the numbers. I am going to write them down for future use if needed.

 

Even if the wire is a bit long, you can fold it up and use a zip tie to shorten it. Your choice.

 

This wire is around 12inches maybe a little more so it looks to be good. I'm going to pull it up on some ramps in the morning for more room for me to work. Thankfully it seems to be easy to access. The connection will take a little longer. I got some electronic cleaner for the connections. Maybe changing them both will help with gas millage? lol

 

Just FYI, the part numbers are available here by year, make and model for future reference - https://ngksparkplugs.com/en/part-finder

 

Thanks.
I do have another question not related to thread. I bought a new cushion and cover for the driver side seat. I'm just curious. Have you ever did yours? I can see the bolt but for my life can't get anything in there. The seat move back and forth but really slow. I figured it was time when the cushion was removed to clean and maybe oil track. The only other option I see , is to remove the seat out completely but with rain coming in. That will have to wait till maybe next weekend. I can see the bolts to remove the cushion. they are in a bad spot to get to. Didn't know if you have dealt with this issue?

 

Update: Soaked all night and it came out easy so replaced it and guess what. Took for a drive after disconnecting battery since my reader didn't clear the code but anyway, it's back on. PO138 O2 CIRCUIT HIGH VOLTAGE ( BANK 1 , SENSOR 2).
After some more research. It's sounding like the down stream may be the one acting up. Focusing on changing the that one this weekend. Will update after it's changed. Thanks

 

Bank one sensor 2 is the post cat sensor.

 

Post is before cat but I changed that one. Upstream is before and downstream is after correct?