P0138 and P0139 codes after off-roading 2nd gen tacoma

After some vigorous off-roading and changing out a busted CV axle my check engine light came on in my 2007 4 liter tacoma. After running the codes I'm getting a P0137, P0138 as well as a P0606 ECM code. I'm fairly confident it's not the ECM after doing some reading.

Both the other codes have to with the Bank 1 sensor 2 Oxygen Sensor that is downstream from the cat on the passenger's side I believe.

It's possible it got some water damage or I banged it against something. I didn't see any visible damage to the wiring harness or the sensor although it's in a very vulnerable place. I have no doubt I got a ton of mud and water all over in that area.

Has anyone had both these codes at the same time? The truck has no other visible symptoms besides the check engine light and those codes.

I'm trying to figure out a line of attack and don't want to get taken for at a dealership.

 

I'd start by pulling apart the connector and making sure it's clean and dry. Slather some dilectric grease in there just for good measure and then, assuming that's not the problem, if you've got a DVOM or scan tool with a live-data reading capability, you can do a pretty conclusive diagnosis yourself. Get the specs for the sensor (should be easily available from members here). Ensure that the sensor is getting power and control voltage (or just power, depending on the type), and then verify the sensor the same way.

 

I don't have a DVOM scan tool but I do have a multi tester. I can at least make sure it's getting the correct power.