P1400 – EGR System Low Flow (Nissan)

Description

The ECM detected insufficient EGR flow.

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Symptoms

  • Rough idle
  • High NOx emissions

Causes

  • Clogged passages
  • Valve sticking
  • Vacuum leak

Diagnosis

  • Inspect EGR passages
  • Test valve
  • Check vacuum lines

Repair

  • Clean passages
  • Replace valve

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