P2422Generic code

P2422 Code: Evaporative Emission System Vent Valve Stuck Closed

The P2422 code means the vent valve on the charcoal canister has stuck closed. The fuel tank cannot breathe, so you may have trouble filling up or see pressure or vacuum build in the tank. Dirt or water in the valve or its filter is the usual cause.

Severity
Low
Can I keep driving?
Yes, no immediate risk
Estimated cost
$40 to $350
Difficulty
Easy
System
Emissions Control
Applies to
All OBD2 vehicles

Common in: Toyota

Updated Reviewed by Renzo Chacca

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What the P2422 code means

The vent valve connects the charcoal canister to the outside air. It sits open almost all the time so the tank can breathe, and it closes only during the leak test. If it stays closed, the tank builds up pressure or vacuum.

The usual cause of a P2422 code is dirt, dust or water inside the valve or the vent filter, which is often under the vehicle near the tank. On roads with a lot of dust and dirt it is very common.

With the valve closed, the fuel pump nozzle at the gas station shuts off again and again while you fill up, because the air in the tank has nowhere to go.

P2422 code symptoms

  • Check engine light on.
  • The gas pump nozzle keeps clicking off while you fill up.
  • A hiss or a whoosh when you open the fuel cap.
  • In extreme cases the fuel tank is deformed by vacuum.

Likely causes of the P2422 code

  1. Vent valve clogged with dust or mud. The most frequent cause.
  2. Clogged canister vent filter. Replace it if you do not know how old it is.
  3. Valve with an electrical fault that left it in the closed position.
  4. Canister saturated with fuel from topping off the tank.

How to diagnose the P2422 code step by step

  1. Locate the valve and its filter, normally next to the canister.
  2. Command it with the scan tool and listen for the click.
  3. Blow through the valve while it is unplugged. Air should pass when it is at rest.
  4. Check the canister for liquid fuel inside it.

How to fix the P2422 code

  • Clean or replace the vent valve and its filter.
  • Replace the canister if it is saturated.
  • Do not keep filling the tank after the pump shuts off the first time.
  • Clear the codes and complete the EVAP monitor.

Technical reference data

  • The valve is normally open and closes only during the leak test.
  • Typical coil resistance: 15 to 30 ohms.
  • Approximate values only: check the manufacturer data for your vehicle.

Brand-specific notes

The P2422 code often shows up first as a fuel pump nozzle that will not stay on. If that is happening to you, check the vent valve and filter before anything else.

P2422 on Toyota, Lexus, Honda and Acura

Very common on these makes.

P2422 on Pickup Trucks Used on Dirt Roads

Common on used pickups that spend their time on dirt roads, where dust clogs the valve.

Frequently asked questions about P2422

Can I drive with a P2422 code?
Yes, but it may be hard to fill the tank. The P2422 code does not affect how the car drives.
Why does the gas pump keep shutting off?
Because the air inside the tank cannot get out through the vent. The nozzle senses the backup and clicks off.
Can the valve be cleaned?
Sometimes. If water has gotten in, it is better to replace it.
What does the P2422 code mean?
It means the EVAP vent valve is stuck in the closed position, so the tank and canister cannot breathe.
How much does it cost to fix P2422?
Roughly $40 to $350. A cleaning or a new vent valve and filter is at the low end, and a new canister costs more.

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