P2431
Secondary Air Injection System Air Flow/Pressure Sensor Circuit
The ECU detects a general fault in the secondary air injection system air flow or pressure sensor circuit. The diagnostic cannot verify proper SAI operation.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Defective SAI sensorCommon
- SAI sensor wiring faultPossible
Parts involved
- Sai Pressure Sensor
- Sai Wiring
P2431 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.