P04EF
EVAP System Very Small Leak Detected Fresh Air Side
Same as P04EE on the fresh-air side - microcrack in a hose or imperfect vent valve seal at the most sensitive test threshold.
Same as P04EE on the fresh-air side - microcrack in a hose or imperfect vent valve seal at the most sensitive test threshold.
Common causes
- high
Vent valve seal aged
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-280
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P04EF mean?
P04EF means "EVAP System Very Small Leak Detected Fresh Air Side". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P04EF?
vent valve seal aged — 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.
Can I keep driving with this code?
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.
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