Error code P2178 - Engine running too lean (Solution)

The error code P2178, "System too lean at idle," is detected by measuring the lambda sensor or the mass airflow sensor.
Identical Error Codes: P2178 / 008568

Possible Causes:
- Excessive fuel supply (leaks at the fuel injector valve)
- Clogged air intake to the engine (air filter)
- Incorrect fuel pressure sensor (G247) installed
- Defect in the mass airflow sensor or its wiring (check the values for plausibility)

The error code P2178 refers to cylinder bank 1 of the engine, and error code P2180 indicates the same issue for cylinder bank 2.