P0131
DESCRIPTIONRefer to DTC P0130 & P0136.
FAILURE CONDITIONS
After the Front Oxygen Sensor Heater is on for 3 minutes, the ECM continuously measures the front oxygen sensor 5 output in 0.5 second intervals. If during two driving cycles the front oxygen sensor's output falls below 50 millivolts for 0.5 seconds, the ECM will set P0131 and MIL will turn on. This code indicates an unusually lean fuel air mixture being read by the front oxygen sensor or ECM.