P04EE

  • Powertrain
  • Generic (SAE)
  • Emissions
SeveritySeverity level 3 of 5: Diagnose soon.

Diagnose soon

Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.

Standard definition

EVAP System Very Small Leak Detected Fuel Tank Side

This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.

In plain English

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.

A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.

Can I keep driving?
Safe to drive
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Urgency
Diagnose soon
Will it pass emissions
No
Check engine light
Solid
Symptoms you may notice
  • Possible smell of fuel near tank or engine bay
  • Failed emissions inspection
  • Loose-cap warning may appear

Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.

Likely causes
#CauseHow oftenComponent
1Fuel cap O-ring aged or stiffenedVery common

Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.

Components involved
  • Fuel Cap
  • Fuel Sender Seal
  • EVAP Hose Tank Side
Sources
Definition
Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
Diagnostic guidance
Written and reviewed in-house. See our editorial policy.
Review status
Awaiting review

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