P0174
System Too Lean (Bank 2)
Medium — service soonPowertrain (engine & transmission)
System
Powertrain (engine & transmission)
Type
Generic (standardized)
Subsystem
Fuel & air metering
What it means
Same lean condition as P0171 but on bank 2 of a V-engine.
Symptoms
Rough idle, hesitation, reduced power.
Common causes
Vacuum leak, dirty MAF, weak fuel delivery or clogged injectors.
Recommended action
Inspect for intake leaks and the MAF sensor; P0171 + P0174 together point to a shared cause like the MAF or fuel pump.
Related codes
P0300Random/Multiple Cylinder Misfire DetectedP0301Cylinder 1 Misfire DetectedP0302Cylinder 2 Misfire DetectedP0303Cylinder 3 Misfire DetectedP0304Cylinder 4 Misfire DetectedP0420Catalyst System Efficiency Below Threshold (Bank 1)P0430Catalyst System Efficiency Below Threshold (Bank 2)P0171System Too Lean (Bank 1)P0172System Too Rich (Bank 1)P0175System Too Rich (Bank 2)P0101Mass Air Flow (MAF) Circuit Range/PerformanceP0113Intake Air Temperature Sensor Circuit High
FAQ — P0174
What does code P0174 mean?
System Too Lean (Bank 2). Same lean condition as P0171 but on bank 2 of a V-engine.
What are the symptoms of P0174?
Rough idle, hesitation, reduced power.
What causes P0174?
Vacuum leak, dirty MAF, weak fuel delivery or clogged injectors.
What should I do about P0174?
Inspect for intake leaks and the MAF sensor; P0171 + P0174 together point to a shared cause like the MAF or fuel pump.
General reference based on the SAE J2012 standard. Exact causes for your vehicle may differ — when in doubt, consult a workshop.
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