You can google the unknown codes. For instance: http://engine-codes.com/p1155_toyota.html The P1155 comes up as "P1155 Toyota - Air/Fuel Ratio Sensor Heater Circuit Malfunction Bank 2 Sensor 1" Did they all occur at once? Slowly creep up? All of those makes me think it's either a faulty ground, or perhaps an old battery, maybe low system voltage. Can you read the battery and see how old it is? Almost wonder if one whole connector to the ECU popped off.