Secondary Air Injection System Insufficient Flow (Bank 1)
AIR system flow on bank 1 is below threshold during the cold-start self-test — typically a clogged check valve, leaking hose, or weak air pump.
Affected components
- Secondary air injection pump
- Secondary air check valve
Common causes
- High likelihood: Check valve clogged with carbon
- Medium likelihood: Air pump weak
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.