P2421EVAP Vent Valve Stuck Open
The evaporative emission system vent valve does not close on command. The ECU detects that the evap system cannot hold pressure or vacuum because the canister is permanently vented to atmosphere.
Can I keep driving? With caution
You can drive to the shop, but do not postpone the repair. The problem may worsen and damage other components.
Sistema Afectado
Motor · Powertrain
La falla pertenece al grupo motopropulsor (motor y gestión electrónica).
Espacio para vendedores de repuestos
Aún no hay un anunciante en este espacio.
Symptoms You Will Notice
What you may observe when this code appears
- Check engine light on Possible smell of fuel near tank or engine bay Failed emissions inspection Loose-cap warning may appear
Possible Causes
The components or conditions that trigger this code
- 1Vent valve mechanically stuck open Dust/debris preventing valve seat Carbon or debris buildup preventing free movement
How to Fix It — Step by Step
Recommended diagnostic and repair procedure
- 1Difficulty: easy. Estimated time: 0.3-1 hours. Estimated cost: €60-€
- 2DIY possible
Note: This information is for general reference. For precise diagnostics and safety repairs, always consult a certified mechanic.
Estimated Cost
Approximate range in USD (varies by region and shop)
Varies by diagnosis
* Diagnosis only: $50–$150
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