P2421 Fault Code

Evaporative Emission System Vent Valve Stuck Open

• What does that mean?
• Symptoms
• Causes
• Solutions

The P2421 fault code indicates that the Evaporative Emission System Vent Valve is stuck in the open position. This valve is crucial for controlling vapor from the fuel tank, preventing harmful emissions from escaping into the atmosphere. When the valve is stuck open, it can lead to fuel vapor leaks, resulting in increased emissions and potential failure of emissions testing.

What are the symptoms of the P2421 code?

Common symptoms associated with the P2421 code include:

• Check Engine Light illuminated on the dashboard
• Decreased fuel efficiency
• Difficulty starting the engine
• Strong gasoline odors around the vehicle
• Failed emissions test due to excessive vapor release.

What causes the P2421 code?

Several factors can contribute to the P2421 fault code, including:

• A defective vent valve or solenoid
• Electrical issues such as short circuits or poor connections
• Blockages in the evap system, such as a damaged hose or charcoal canister
• Faulty engine control module (ECM) triggering false codes.

How to fix P2421?

To address the P2421 fault code, the following steps should be taken:

• Inspect the evap system for visible signs of damage or blockages
• Test the vent valve operation; replace if faulty
• Check wiring and electrical connections for continuity and integrity
• Clear the fault code and perform a smoke test to ensure there are no leaks in the system
• If issues persist, further diagnostics may be needed on the ECM.