What does Huatai Santa Fe 2.0 diesel version mean by excessive air flow?

P 1 1 12 fault code belongs to the factory-defined fault code. This is not a common EOBD fault code. Therefore, the explanation of the meaning of the fault code may not be appropriate-the air-fuel ratio control system in column1is too strong. That is, PCM monitors that the signal voltage value of the oxygen sensor is in a high voltage state, that is, the air-fuel ratio AFR: 1 less than 1. Check the pressure of the fuel system, clean the oxygen sensor and check the injection timing.

Don't ignore whether the oil return pipe is unblocked.