P0400

Error Code P0400: Exhaust Gas Recirculation Flow Malfunction

Severity: Medium

What does P0400 mean?

Exhaust Gas Recirculation Flow Malfunction

Symptoms

  • Rough idle
  • Engine ping/knock
  • Failed emissions test
  • Check engine light

Common Causes

  • Carbon-clogged EGR valve
  • Faulty EGR solenoid
  • Blocked EGR passages
  • Faulty EGR sensor

How to Fix

  1. Clean or replace EGR valve
  2. Check EGR solenoid
  3. Clean EGR passages
  4. Replace EGR position sensor

Frequently Asked Questions

What does error code P0400 mean?

Exhaust Gas Recirculation Flow Malfunction. This is a medium severity issue that should be addressed soon.

Can I clear P0400 with Cars Guru?

Yes. Connect your ELM327 OBD2 adapter, scan your vehicle with Cars Guru, and you can read and clear the P0400 fault code. Our AI will also explain the issue in plain language and suggest next steps.

Is it safe to drive with P0400?

It depends on the severity. Cars Guru rates this code as medium. We recommend addressing the root cause before continuing to drive. Use Cars Guru's AI diagnostics for a detailed assessment.

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