P0411 Secondary Air Injection System Incorrect Flow Detected
What does P0411 mean?
P0411 — Secondary Air Injection System Incorrect Flow Detected. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects secondary air injection system incorrect flow detected. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0411
- Failed secondary air injection pump
- Blocked or leaking air injection hoses or check valves
- Faulty air injection relay or fuse
- Cracked air injection manifold
- Carbon blockage at the injection ports
How to fix P0411
- Check the secondary air pump fuse, relay, and operation
- Inspect hoses and check valves for leaks or blockage
- Listen for the pump running during cold start on an OBD-II scanner command
- Check the injection manifolds for cracks and carbon plugs
- Replace failed pump, valves, or hoses as found