What it means
The switching valve on bank 2 will not open when commanded, so no secondary air reaches the exhaust during cold start. Catalyst light-off is delayed and emissions during the cold-start window rise.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
On Bank 2, the secondary air injection switching valve routes pump air into the exhaust during cold start to help the catalyst warm up. The engine control module checks whether the valve responds when commanded open. P2443 sets when the Bank 2 valve is detected as remaining closed, restricting that airflow.
Common causes
Most likely first.
- Switching valve stuck closed
- Carbon or debris buildup preventing free movement
- Component wear with age - mechanical play
Symptoms
- Check engine light on
- Rough idle or hesitation during cold start
- Reduced engine performance
- Failed emissions inspection
How to diagnose it
- Use a scan tool to review freeze-frame data and compare the commanded Bank 2 valve state with air-system and oxygen-sensor readings during a cold start.
- Inspect the Bank 2 valve, its connector, wiring, and nearby air hoses for damage, loose connections, or signs of heat and corrosion.
- With the system safely cool, check whether the Bank 2 valve moves freely and look for carbon or debris obstructing it.
- Check the valve’s power, ground, and control circuit while it is commanded open, following the wiring diagram and manufacturer’s specification.
- If the valve and circuit operate correctly, check the Bank 2 air passage and pump output for a blockage or other restriction.
Common fixes
- Clear debris or carbon that is preventing the Bank 2 switching valve from moving.
- Repair damaged wiring or clean and secure the valve connector.
- Replace a worn or mechanically stuck Bank 2 switching valve.
- Repair a blocked or damaged air hose or passage.
Can I keep driving?
The vehicle may be drivable if it runs normally, but avoid relying on it to pass an emissions inspection. Cold-start emissions can rise, and rough idle or hesitation may occur until the Bank 2 air valve works.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.