P1147 – HO2S21 Indicates Rich (Ford)

Description

P1147 Ford indicates the downstream O2 sensor on Bank 2 is stuck rich.

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Symptoms

  • Rough idle
  • High fuel consumption
  • Black smoke

Causes

  • Leaking injector
  • Fuel pressure too high
  • Short to power

Diagnosis

  • Check fuel pressure
  • Inspect injectors
  • Scan O2 data

Repair

  • Replace injector
  • Repair wiring
  • Replace O2 sensor