What does it mean?
P1416 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Secondary Air Injection System (Bank 2) Malfunction .
Symptoms
- MIL on with an incomplete secondary air monitor
- Cold start emissions higher than normal, with a raw fuel smell
- Slightly uneven idle when the engine is cold, smoothing out as it warms
- Pump noise present but airflow only reaching one side
- Possible whistling or leak noise on the Bank 2 air plumbing during the pump run
Likely causes
- Carbon plugged injection ports in the Bank 2 head or exhaust manifold
- Bank 2 check valve stuck closed, or stuck open and letting exhaust pressure back up the line
- Split or disconnected air hose feeding the Bank 2 side only
- Bank 2 combination or shut off valve not opening due to a vacuum leak in its control line
- Weak air pump that can supply one bank but not both
- Bank 2 upstream oxygen sensor slow or biased, so the lean shift is not recognised
- Cracked exhaust manifold on Bank 2 letting injected air escape before the sensor
How to fix it
- Compare Bank 1 and Bank 2 upstream oxygen sensor data on a cold start while the pump runs; only the failed bank stays unaffected
- Check the Bank 2 air hose and clamps for splits, heat damage and disconnection
- Remove and inspect the Bank 2 check valve for carbon, sticking and a burnt sealing face
- Apply vacuum to the Bank 2 control valve, or command it electrically, and verify it opens and holds
- Inspect the Bank 2 injection ports for carbon blockage and clean the passages
- Inspect the Bank 2 exhaust manifold for cracks and leaking gaskets ahead of the oxygen sensor
- Replace the faulty valve, hose or pump, then run a cold start drive cycle to confirm the monitor completes