Bank 1 02 sensor

Just got my first check engine light. The scan tool says "Bank One" oxygen sensor. Is that the first sensor or second one?

 

Should say bank 1 sensor 1 or senor 2

 

Here's a page from the FSM that shows what he's describing:


Here's someone with possibly the same situation - looks like you could try cleaning the MAF (inexpensive and easy) - what code is it throwing?
http://www.customtacos.com/forum/127-1995-5-2004/86629-o2-sensor-bank-1-sensor-1-low-input.html

 

Just got the same code today after wheeling. It was super dusty out so I cleared it for now assuming the truck just needed time to clear out.

As the above have said it should be sensor 1