Error code
OBD2 P0174
OBD2P0174
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
System Too Lean.
Severity
moderateCan be driven, but performance may suffer and the issue should be addressed soon.
Summary
P0174 indicates that the fuel mixture is too lean in bank 2 of the engine, meaning there's an excess of air relative to fuel.
Symptoms
- Engine misfires
- Poor acceleration
Common Causes
- Intake/exhaust leak
- Fuel pressure/pump issues
- Faulty injectors or air system
Diagnosis
- Check for intake/exhaust leaks
- Inspect fuel pressure and pump functionality
- Verify air system components like MAF sensor
Fixes
- Repair or replace faulty parts such as vacuum hoses, fuel injectors, or the Mass Air Flow (MAF) sensor
FAQ
What does a lean condition mean?
A lean condition means there's too much air and not enough fuel in the engine mixture.
How can I check for vacuum leaks?
You can use a smoke machine or observe STFT readings at idle and full throttle to detect leaks.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- P0100Mass or Volume Air Flow Circuit
- P0101Mass or Volume Air Flow Circuit Range/Performance
- P0102Mass or Volume Air Flow Circuit Low Input
- P0103Mass or Volume Air Flow Circuit High Input
- P0104Mass or Volume Air Flow Circuit Intermittent
- P0105Manifold Absolute Pressure/Barometric Pressure Circuit
- P0106Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance
- P0107Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
- P0108Manifold Absolute Pressure/Barometric Pressure Circuit High Input
- P0109Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
- P0110Intake Air Temperature Sensor 1 Circuit
- P0111Intake Air Temperature Sensor 1 Circuit Range/Performance