P0171 VOLKSWAGEN - System Too Lean Bank 1
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection
2002 Volkswagen Passat
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- The amount of mixture ratio compensation is too small. (The mixture ratio is too lean.)
- Excessive Fuel Consumption
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).
What is the most likely fix for this code? Air Filter? Air Flow Meter? etc....
also a po688 is reading...
well my car will start and idle hard then shut back off its giving a too lean code and a po174 code ...
I HAVE REPLACED everything listed for the CEL codes: P0171 and P0440 always together. 1997 VW Golf...
Any information is appreciated. Thanks