Secondary Air Injection Downstream Flow Fault
Findings, check these first
- Failed air pump
- Blocked downstream air passages
- Failed diverter or check valve
- Split air injection hoses
- Blown air pump fuse or relay
Standard procedure
- Verify pump operation on cold start
- Check the pump fuse and relay
- Inspect hoses and check valves
- Test for downstream flow at the manifolds
- Replace the pump or valves per flow tests
Code lookup
Type a code above, or start from a symptom or a common code.
Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.
Sources and review
Review: checked against the recorded source material.
- OBDII.pro: P1411 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1411: SAI System Incorrect Downstream Flow Detected
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
- P1411 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1411: Secondary Air Injection Downstream Flow
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.
Last updated 2026-09-06.
Report a correction for P1411. Include your vehicle, the issue and a source if you have one.