OBD-II FAULT CODE
P0172
Fuel Trim too Rich (Bank 1)
Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0172.
- Check Engine light
- Poor drivability or reduced fuel economy depending on fault
- Poor fuel economy
- Fuel smell
- Black smoke in severe cases
- Leaking injector
- Faulty fuel pressure regulator
- Contaminated MAF/MAP reading
- EVAP purge stuck open
- Scan all modules and record freeze-frame data before clearing codes
- Check battery voltage and related fuses
- Check fuel trims, fuel pressure, injector leak-down and purge valve operation
- Repair leaking injector/pressure issue, clean/replace faulty airflow sensor, repair purge system fault
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Disclaimer: Information is provided for general guidance only and may not apply to all vehicles. Always consult a qualified technician.