P0450
EVAP System Pressure Sensor/Switch A Circuit
A general electrical fault on EVAP pressure sensor/switch A — used to monitor canister pressure during leak-detection diagnostics.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Common causes
Ordered by how often each turns out to be the cause.
- Sensor failedCommon
Parts involved
- EVAP Pressure Sensor
P0450 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.