Can't find info for code PO135

Question

Code PO135 shows up, no information is showing for this code. What does code PO135 mean.

Answer 1

P0135 - 02 sensor heater circuit malfunction (Bank 1 Sensor 1)

Bank 1 is where cylinder number 1 is located and being sensor 1 this is the upstream 02 sensor. What set this code is either a open in the heater circuit of the 02 sensor or a shorted heated  02 sensor.