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P0171
P0171: System too lean (Bank 1)
Severity: Medium — fix it soon
P0171 means the oxygen sensor sees too much oxygen — the mixture has too much air — and the computer has reached its fuel-trim correction limit.
Common causes
- Vacuum leak from a hose or intake gasket.
- Dirty or faulty MAF sensor.
- Clogged fuel filter or weak pump.
- Dirty injectors.
How to check
Watch live short/long-term fuel trim. High at idle that drops at higher RPM usually means a vacuum leak; high everywhere points to fuel delivery or the MAF.
How RA-150 helps
Plug the Raqib RA-150 into the OBD port, open the app and tap Scan: you get the exact code, a plain explanation, and the AI assistant tells you what to do. After the repair you can clear the code and check it doesn't return.
Read the code yourself with Raqib RA-150
Bluetooth scanner + Arabic app and AI assistant. Made and packaged in Egypt.