P1146 – HO2S21 Indicates Lean (Ford)

Description

P1146 Ford indicates the downstream O2 sensor on Bank 2 is stuck lean.

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Symptoms

  • Hesitation
  • Poor acceleration
  • High fuel trims

Causes

  • Vacuum leak
  • Exhaust leak
  • Weak fuel pressure

Diagnosis

  • Check fuel trims
  • Smoke test intake
  • Inspect O2 sensor

Repair

  • Repair leaks
  • Replace O2 sensor