P0411 – Secondary Air Injection Incorrect Flow
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Symptoms
- Rough idle
- Hesitation
- Poor acceleration
- Cold start issues
- Check engine light
Causes
- Faulty air pump
- Stuck check valve
- Vacuum leak
- Blocked hose
- Relay failure
Diagnosis
- Inspect air pump
- Check valves
- Inspect hoses
- Test relay
- Scan live data
Repair
- Replace air pump
- Replace valves
- Fix vacuum leaks
- Replace hoses
- Replace relay