I recent noticed that for the 3rd gen Priuses (Prii) depending on the year use different upstream O2 sensors (the one closest to the engine). From what I have seen Sensor number 234-9090 are in: 2010,2014,2015 Sensor number 234-9112 are in 211,2012 I am just wondering why is that? Are the 2 part interchangeable? Thanks.