P0411 Secondary Air Injection System Incorrect Flow Detected

Powertrain Severity: Low Generic OBD-II

The secondary air flow is not as expected.

Common causes

  • Weak air pump
  • Stuck check valve
  • Leaking hose

Symptoms

  • Check engine light

What to check

  1. Inspect hoses
  2. Test check valve
  3. Check pump output

Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0411, follow the service information for that make and model.

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