987 · Fuel

P0173

Fuel Trim Malfunction (Bank 2)

MED SEVERITY

Bank 2 fuel trim is out of the normal correction range.

SYMPTOMS

  • Check-engine light
  • Rough idle
  • Hesitation

LIKELY CAUSES

  • Vacuum/intake leak
  • Dirty or failing MAF
  • Fuel pressure issue
  • Faulty O2 sensor
  • Leaking or clogged injector

DIAGNOSIS STEPS

  • Read short- and long-term fuel trims
  • Smoke-test the intake
  • Verify fuel pressure
  • Check MAF and O2 live data

RELATED PARTS

  • MAF sensor
  • Fuel pump
  • Intake gaskets
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