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P0174

System too lean (Bank 2)

Fuel-trim monitoring indicates that Bank 2 is running leaner than the ECU can correct within its normal range.

What this code means

Fuel-trim monitoring indicates that Bank 2 is running leaner than the ECU can correct within its normal range.

Possible causes

  • Vacuum or intake air leak
  • Low fuel pressure
  • Restricted fuel delivery
  • Incorrect MAF reading
  • Exhaust leak affecting oxygen-sensor readings

Common symptoms

  • Check engine light
  • Rough idle
  • Hesitation
  • Reduced power
  • Possible misfire

Checks to make

  1. Inspect intake hoses and vacuum lines
  2. Check for related fuel-trim or misfire codes
  3. Review fuel-trim live data
  4. Check fuel pressure where appropriate
  5. Inspect MAF readings and relevant sensor data

Safety

  • Work around a running engine only when necessary and keep hands, clothing and tools clear of moving or hot components.

Model notes

Bank 2 is the cylinder bank opposite Bank 1 on engines with two banks.