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Home >> Mazda >> 2012 >> 6 i Touring >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 20 (On-Board Diagnostic [Engine Controls MZI 3.7] (2 Of 5)) >> DTC P0171:00, P0174:00 >> Notes

DTC P0171:00, P0174:00: Notes

WARNING: This page is about a different variant/trim than selected.
DTC P0171:00 P0171:00: System too lean (RH)
DTC P0174:00 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.
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