P1131 and P1151 are lean codes for banks 1 & 2.
This can be the upstream sensors going out (over about 80k miles) since the upstream sensors control fuel trim.
These codes can also be caused by low fuel pressure, dirty MAF, vacuum leaks...
At 110k miles, I would go ahead and replace the upstreams if they are original.
There should be no reason to replace the downstream sensors. They only alert the computer if they sense CAT problems. They do not affect engine operation and rarely go bad because they stay clean behind the CATs.
Most places will accept full return if merchandise is unused.
