I was trying to save some money on my 9 year old Prius so I took it to a reputable nearby Americas Tire store to have it fitted. They charged me $120 for installments. All 4, after install the TPS light is still on, the installer told me to give the system a few days to recognize it. I waited a week, the TPS lights flashed on every start and became constant after 15 seconds so I went back to Americas Tire, they use their TPS machine to check all the sensors, they all read fine they told me , I should either find another place to program or spend $330 to install your sensor. Now I'm stuck!