OBD Guide

P04EF

EVAP System Very Small Leak Detected - Fresh Air Side

P04EF is an OBD-II diagnostic trouble code meaning: EVAP System Very Small Leak Detected - Fresh Air Side. Common causes: damage to evap system hoses, leaking fuel cap. Estimated repair cost: $22–111.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–111 (est.)

Symptoms

  • Check Engine Light Is On
  • Slight increase in fuel consumption
  • Smell of fuel in the cabin

Causes

  • Damage to EVAP system hoses
  • Leaking fuel cap
  • Purge valve malfunction
  • Damage to the adsorber

How to Fix

  1. Check the tightness of the fuel tank cap
  2. Inspect the EVAP system hoses for damage.
  3. Check the purge valve for functionality
  4. Carry out diagnostics of the EVAP system at a service station

Related codes

Error P04EF by Vehicle Brand

FAQ

What does the P04EF code mean?

P04EF is an OBD-II diagnostic trouble code that indicates: EVAP System Very Small Leak Detected - Fresh Air Side

What causes a P04EF error code?

The most common causes of P04EF include: Damage to EVAP system hoses; Leaking fuel cap; Purge valve malfunction; Damage to the adsorber.

How do I fix a P04EF diagnostic trouble code?

To fix P04EF: Check the tightness of the fuel tank cap. Inspect the EVAP system hoses for damage.. Check the purge valve for functionality. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P04EF?

Limited driving only, diagnose soon

How much does it cost to fix P04EF?

The estimated repair cost for P04EF is $22–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat