P04DF

What it means

EVAP System Purge Control Valve A Performance Stuck Open: the component is electrically intact but its response does not match the command.

Is it safe to drive?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

• Debris on valve seat prevents full closing

  high

  One of the most commonly reported causes for this code — check this first.

• Return spring weakened

  medium

  A plausible cause — test and verify before replacing parts.

• Carbon or debris buildup preventing free movement

  low

  Less common, but worth ruling out after the more likely causes.

Related help

• Full P04DF diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?