Air/Fuel Ratio Sensor, P11221, P0171- are all these things related?

I apologize in advance for this long post but this is complicated and I need help! About about a year ago I ran over a large tree limb in the road. The limb came up and went into the grill, tore the bumper and essentially broke the A/C condenser and radiator. First mistake was to take it to a body shop that didn't work on Priuss'. They made the body repairs fine. I had to take it back for three "emergency" Red exclamations coming on, on three separate occasions. Out of those times they had to 1 - replace hoses and a tank assembly, 2 - replace the coolant reservoir tank and radiator drain petcock, 3- replace the after market radiator they put in and use a Toyota one because they determined that was the source of all the issues. (mind you at this time they had the car for almost 20 days!)
Once they did that I had the car back a few months (i only drive it once a week, around 50 miles) and a check engine light comes on. At that time the codes were P1121 and P0171. When they told me what the P1121 (Coolant Flow Control Valve) was I researched it and found that it could be directly related to them putting in a bad radiator and the car running on that messed up the Coolant Flow Control valve. They agreed and replaced it, and claimed they couldn't get the P0171 to come on again after replacing the coolant control valve. Now another month goes by (again very minimal driving) and the P0171 code comes back on. I take it back in, they run a bunch of tests and are now telling me that code is from the Air / Fuel Ratio sensor has gone bad. They don't want to cover this one as they say it isn't connected to their shotty workmanship. My question (if you've gotten this far, thank you!!) is can this Air / Fuel ratio sensor be a result of previous bad work on things such as the A/C condenser, radiator, coolant flow, etc etc??