Bank 2 refers to the side of the engine opposite of the number one cylinder. Sensor 1 refers to the first sensor in the exhaust from the engine, the one before the catalytic convertor.
Trouble code P0154 means: O2 Circuit No Activity Detected (Bank 2, Sensor 1)
Trouble code P0140means:O2 sensor ciruit-no activity detected (bank 1 sensor 2)
Trouble code P0140 means:O2 sensor circuit no activity detected (Bank 1 Sensor 2)
Trouble code P0340 means: Camshaft Position Sensor A Circuit (Bank 1 or single sensor)
Trouble code P0134 means:O2 sensor circuit no activity detected (Bank 1 Sensor 1)
It means your sensor heater in Sensor 1 or Bank 1 is malfunctioning. Get it replaced.
02 sensor. Bank 1 Sensor 3, post cat
P0139 02 Sensor Circuit Slow Response (Bank 1 Sensor 2)
Trouble code P0134 means:O2 sensor circuit no activity detected (Bank 1 Sensor 1)
Trouble code P0142 means:O2 sensor circuit malfunction (Bank 1 Sensor 3)
Trouble code P0156 means:O2 sensor circuit malfunction (Bank 2 Sensor 2)
O2 Sensor Heater Circuit (Bank 1 Sensor 1)