Service bulletin - The MIL comes on with DTC P0134 (rear A/F sensor [bank 1, sensor 1] heater system malfunction) and/or P0154 (front A/F sensor [bank 2, sensor 1] heater system malfunction). The PCM misinterprets the heater system input from the A/F sensor and sets DTC codes P0134 and/or P0154.
