P0171

P0171

Oxygen Sensing Adaptation, Idle Range, Bank 1 - Above Limit

Diagnosis conditions
- Oxygen sensing system active
- Time elapsed after engine start-up: 250 to 350 seconds (USA)
- Time elapsed after engine start-up: 302 to 402 seconds (RoW)
- Engine temperature greater than 60 °C

Possible fault cause
- Incorrect signal from MAF sensor
- Intake air system leaking
- Fuel pressure too low
- Volume supply of fuel pump too low
- Fuel injectors fouled
- PCV valve leaks
- Cap of oil filler neck not closed correctly or seal is damaged

Diagnosis/Troubleshooting

NOTE:
- Air leaks ahead of the oxygen sensors can lead to a fault in adaptation See Check exhaust system for leaks.
- Contrary adaptation values in connection with misfiring point to incorrectly adjusted control times See check control times and adjust if necessary.
- If the fuel tank reserve light is switched on, no fault is entered.

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Part 2: