Check engine light, showing codes P2195 and PO138

In the 10 years I've had my 2011 Tacoma 4.0, yesterday was the first time the check engine light has turned on.
First thing I did this morning was walk to the auto parts store and buy a can of MAF cleaner, and also borrowed a code scanner. The MAF definitely needed cleaning.
Didn't seem to make a difference in the CEL.
The codes P2195 and P0138 showed, an online search indicates this means the o2 sensor isn't operating within a normal range, and the fuel/air ratio is off. The P2195 code suggests the truck is running lean, but the P0138 code suggests the truck is running rich, read from the downstream o2 sensor. How can this be?
Would this mean there is an issue with the catalytic converter? Is there a way to specifically test the cat?

Any thoughts or ideas on this? It's a month to book anywhere for a mechanic in my area. As this is my work truck I'm going to need to keep driving and hope it ok to do so until I get to a shop.

 

I suspect you have a failing AFR (Upstream) sensor on bank 1 (passenger side).

Do you have a scan tool that can read data so you can monitor O2 sensor data and fuel trims?

 

I don't have a scan tool of my own but decided it's time to have one.

I may just order a quality O2 sensor for upstream and replace it myself and see if that does the trick.

After a bit of digging online this afternoon, I did see on another forum a topic identical to mine, and the advice was the same, to replace the upstream one.

 

Yea it's pretty much a must have if you plan on doing any DIY repairs.

Denso is the OEM manufacturer, I don't recommend getting one off Amazon/Ebay as there are too many fake and questionable parts on there. Get one from Rock Auto, a dealer, or a parts store.

It could be the downstream (or something else) but the upstream is the one that is primarily in charge of fuel control so if it starts lying and reporting a false lean condition the PCM will add more fuel than necessary and the downstream sensor will then report that it's too rich.
Without being able to monitor O2 and fuel trim activity over various conditions though best guess based on the codes is a skewed/lying upstream sensor.
Make sure that there is no oil or other contamination leaking onto any of the sensors and/or sensor wires as that can poison them and cause them to read incorrectly.

 

New o2 sensors installed, end of problem.