OBD Guide

P2421

EVAP System Vent Valve Stuck Open

P2421 is an OBD-II diagnostic trouble code meaning: EVAP System Vent Valve Stuck Open. Common causes: stuck evap vent valve, open or short circuit in valve circuit. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Check Engine Light Is On
  • Increased fuel consumption
  • Smell of gasoline in the fuel tank area
  • Unstable engine idling
  • Dips during acceleration

Causes

  • Stuck EVAP vent valve
  • Open or short circuit in valve circuit
  • Damaged wiring harness
  • Engine control unit malfunction
  • Mechanical damage to the valve

How to Fix

  1. Check the condition of the EVAP vent valve
  2. Test the valve electrical circuit
  3. Check valve coil resistance
  4. Replace faulty valve if necessary
  5. Clear error codes and check the system

Related codes

Error P2421 by Vehicle Brand

FAQ

What does the P2421 code mean?

P2421 is an OBD-II diagnostic trouble code that indicates: EVAP System Vent Valve Stuck Open

What causes a P2421 error code?

The most common causes of P2421 include: Stuck EVAP vent valve; Open or short circuit in valve circuit; Damaged wiring harness; Engine control unit malfunction.

How do I fix a P2421 diagnostic trouble code?

To fix P2421: Check the condition of the EVAP vent valve. Test the valve electrical circuit. Check valve coil resistance. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P2421?

Yes, but get it checked soon

How much does it cost to fix P2421?

The estimated repair cost for P2421 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

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