A 2017 Audi A4 with a mileage of approximately 13000km and a CWN engine and OCK transmission the engine light is on while driving. Scan the car and read the code: P017200 – system too rich (Bank 1). This means there is more oil and less oxygen.

Possible causes are below:

(1) Carbon canister solenoid valve, carbon canister, fuel vapor pipeline failure;

(2) Gasoline at the high-pressure fuel pump leaks to the crankcase;

(3) Incorrect installation of gasoline filter (400kPa installed to 600kPa);

(4) Failure of the fuel injector;

(5) The air filter and pipeline failure lead to poor air intake;

(6) The sensor error signal results in an error in the load signal;

(7) Excessive carbon deposits in the combustion chamber;

(8) Oxygen sensor failure;

(9) Internal failure of engine ECU;

(10) Other failures.


Fix process:

1. Compare normal vehicle mixed gas data stream with faulty vehicles.

2. The mixed gas in the vehicle data stream is short-term matched. The data of cylinder bank 1 (-21.875%) is significantly higher than that of normal vehicles (4.6875%), and the air quality (3.05g) is also significantly higher than normal vehicles (2.36g)

3. Check that the air filter and pipeline are normal.

4. The failure remains after replacing the oxygen sensor.

5. Read the data of the air flow sensor after turning off the ignition, there is a big difference between the normal vehicle and this vehicle. The data of the air flow sensor after the normal vehicle turned off is very small (0.028). The data of the air flow sensor after the faulty vehicle turned off (0.8g) is obviously larger than that of the normal vehicle.

6. The fault light is off after replacing the air flow sensor.


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