Code result
P04B3
Refueling Vapor Control Valve Performance Stuck Open
Moderate severity
What it means
The refueling vapor control valve is stuck open. Vapor pathways meant to be closed except during refueling stay permanently open, distorting EVAP leak diagnostics and allowing vapor flow even with the fuel cap closed.
Is it safe to drive?
Use caution
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
Valve stuck open due to debris or weak spring
highOne of the most commonly reported causes for this code — check this first.
Carbon or debris buildup preventing free movement
lowLess common, but worth ruling out after the more likely causes.
Component wear with age - mechanical play
lowLess common, but worth ruling out after the more likely causes.
Related help
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