Help!! CEL is on Code P0174

[HumminNBoatin']

Ok guys it was 18 Degrees on Friday Morning. I went out to start the H2 to let it warm up. I came back and saw the CEL on. I immediatly went to Advance Auto Parts to get the code pulled. and its
(P0174 system lean Bank 2) I had them reset it and it came on again Saturday morning Very cold morning as well. I had it reset again but it came on again not more than 15 minutes down the road so I know its not a cold start fluke.
So I did some research and looks to be an O2 Sensor. But not really sure witch one it is? I am thinking there are 4 O2 Sensors on the H2?? Anybody have a clue.

I am thinking that I will swap it with another one already on the truck maybe the opposite side and see if the CEL light will follow the problem to (Bank 1) first. If Thats the Case I am think I will try to clean it with some carb cleaner and see if that fixes the problem.

However if the CEL light comes on again and its the same (Bank 2) Does anybody know where I should start???

I am sure HumTech might have some ideas???

Thanks,
Eric