P04EA
EVAP System Small Leak Detected Fuel Tank Side
The EVAP leak diagnostic has detected a small leak on the fuel tank side of the system - typically a hose, gasket, fuel cap, or fuel sender flange that does not seal completely. Vapor escapes during pressure or vacuum tests.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
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.
- Fuel cap not sealing properlyCommon
- Vapor hose porous or crackedPossible
Parts involved
- Fuel Tank
- Fuel Cap
- Fuel Sender Seal
- EVAP Hose Tank Side
P04EA 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.