2003 Honda CRV Check Engine Light

The check engine light has been coming on and going off for a few months now. For financial reasons, we’ve been unable to look into it. Now I have to get the inspection done and we must fix the problem. Took it to Auto Zone and they ran their test. Here’s what the print out reads:

Troubleshooting P0134
OEM Brand: Honda

Definition
ááA/F sensor 1 heater system malfunction
Probable cause
áá1. - Open or short circuit condition
áá2. - Poor Electrical Connection
áá3. - Faulty A/F sensor 1

They also hand wrote on the ticket:
02 sensor bank 1
-for me so I would remember it to tell my husband.

In looking up this code information on the internet, there is a lot of conversation about replacing a sensor, but in the “probable cause" above, it refers to something else.
I’m confused and have no clue which issue(s) should be addressed. I would really appreciate any help/ information you can provide.
My husband is going to try to locate the sensor and see if “cleaning it up" will yield any results.
Where would that be located, specifically?
I’ve read that it’s near the cat. Convertor, but that doesn’t help me much.
Thank you in advance for your information.
JLR