P2443
Secondary Air Injection System Switching Valve Stuck Closed (Bank 2)
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.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Switching valve stuck closedCommon
- Carbon or debris buildup preventing free movementLess likely
- Component wear with age - mechanical playLess likely
Parts involved
- Secondary Air Switching Valve
- Secondary Air Vacuum Lines
P2443 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.