I need to take my truck for an e-check and my check engine light is on, so I went to autozone to have them read the codes. They are P1151, P0156, and P0174. They all have issues on bank 2 so I'm thinking its 02 sensor related. I do have an exhaust leak or two though, could this be the problem? I also had an intermittent code a little while back for the PCV valve, but that just went away on its own.

 

I also had very long crankovers this past winter when the truck was cold, if that could be a related symptom?

 

Be a little careful about this.
1151 and 174 are the same indicator of bank 2 sensor 1 'detecting' the same fault, a lean condition.
It's not the sensor.
0156 is a bank 2 sensor 2 circuit issue.

There could be either one or two faults from these codes.
The lean codes suggest an air leak in the intake tract.
The 156 code suggest a harness issue to that sensor.
.
All sensors have Ox sensing and a separate heaters to heat them faster from a cold start.
Good luck.

 

I ordered 2 o2 sensors already, do you think that was a waste of money?

 

Don't hurt to change them at the age but doubt they are the trouble.
There is more to this than just flying with what you read and not understanding the meanings behind the codes and why they are produced and set..
For example the lean reference of sensor 1 bank 2 means the fuel tables in the computer program have been shifted out of limits to the 'lean' side trying to correct for too much fuel brought on by an air leak.
When the table shifts out of limits the codes are set.
So you can see from this action the OX senor is not the root cause of the issue but only reports it because the system has no other way too report it.
If the sensor where faulty, that is detected with other codes because the system is so good the difference can be detected by other tests.
Bottom line is you just can't run with words you see without understanding the background behind them.
This is why dealer techs and good mechanics go to school on the systems.
Good luck.