
Basic checks
Veepeak OBDCheck BLE
A Bluetooth LE adapter for reading standard engine codes and supported live data.
View on AmazonEVAP System Very Small Leak Detected Fuel Tank Side
Same as P04EA but at the most sensitive leak threshold - typically the OBD-II 0.020-inch (~0.5 mm) test. The system holds pressure for some time but loses it slower than the diagnostic limit allows; usually fuel cap O-ring fatigue or microcracks in a hose.
Same as P04EA but at the most sensitive leak threshold - typically the OBD-II 0.020-inch (~0.5 mm) test. The system holds pressure for some time but loses it slower than the diagnostic limit allows; usually fuel cap O-ring fatigue or microcracks in a hose.
One of the most commonly reported causes for this code — check this first.
Typical part cost: $30-220
Create a free Wrenchify account to unlock the rest for P04EE.
Unlock causesFree forever · No credit card
Create a free Wrenchify account to unlock the rest for P04EE.
Unlock diagnosisFree forever · No credit card
Already have a compatible scanner? Use it. If not, a Bluetooth OBD2 adapter can help you confirm engine codes and check supported live sensor data before replacing parts.

Basic checks
A Bluetooth LE adapter for reading standard engine codes and supported live data.
View on Amazon
Regular diagnostics
A Bluetooth LE adapter with an automatic sleep feature for routine code and sensor checks.
View on Amazon
Another option
A Bluetooth LE adapter to consider when comparing supported vehicles and diagnostic apps.
View on AmazonIllustrations shown, not product photos. Check vehicle, phone and app compatibility before buying. These adapters do not guarantee access to ABS, airbags or manufacturer-specific systems. Clearing a code does not repair the fault and can reset emissions readiness monitors.
As an Amazon Associate, Wrenchify earns from qualifying purchases. This supports the app at no extra cost to you.
Create a free Wrenchify account to unlock the rest for P04EE.
Unlock related codesFree forever · No credit card
P04EE means "EVAP System Very Small Leak Detected Fuel Tank Side". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
fuel cap o-ring aged or stiffened — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
Year, make, model + step-by-step repair help — free plan included.