DTC P0171:00, P0174:00 [MZI-3.7]: Notes
WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
DETECTION CONDITION & POSSIBLE CAUSE
DTC P0171:00
DTC P0174:00 |
P0171:00: System too lean (RH)
P0174:00: System too lean (LH) |
| DETECTION CONDITION |
- P0171:00 indicates that the fuel/air ratio is too lean (RH).
- P0174:00 indicates that the fuel/air ratio is too lean (LH).
- The adaptive fuel strategy continuously monitors the fuel delivery hardware The test fails when the adaptive fuel tables reach a rich calibrated limit.
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| POSSIBLE CAUSE |
Fuel System:
- Damaged or worn fuel pump
- Leaking fuel pump check valve
- Ethanol content in fuel
- Fuel supply line restricted
- Damaged or leaking fuel pulse damper
- Fuel filter plugged or dirty
- Low fuel pressure or fuel nearly depleted
- Purge solenoid valve is leaking when canister is clean
- Leaking/contaminated fuel injectors
Exhaust System.
- Exhaust leaks in exhaust manifold gasket or mating gaskets before or near the A/F sensor
Intake Air System
- Vacuum leaks
- PCV system is leaking or valve is stuck open
- Air leaks after MAF sensor
- Improperly seated engine oil dipstick
- Intake air turbulence due to incorrect air filter
- Contaminated MAF sensor
Electrical System:
- MAF sensor malfunction
- PCM malfunction
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