EVAP System Purge Control Valve A Stuck Closed
Same as P04AF on EVAP purge valve A. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.
Affected components
- Evap purge valve a
Common causes
- High likelihood: Valve stuck closed
- Low likelihood: Carbon or debris buildup preventing free movement
- Low likelihood: Component wear with age - mechanical play
Possible symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.