Question

What is code P0455​?

Engine code P0455 indicates “Evaporative Emission Control System (EVAP) Large Leak Detected,” implying there’s a substantial leak in the EVAP system.

The main job of the EVAP system is to stop gasoline vapors from going into the atmosphere. The powertrain control module logs this error code when it senses a leakage in the EVAP system, which is equivalent to a hole of 0.04-inch diameter or bigger. Mostly, the code P0455 appears in car makes like Chevrolet, Jeep, Ford, Dodge, and Nissan.

What are the symptoms of the P0455 code?

The most evident sign of this engine code is the check engine light getting illuminated. These are some other common signs you can observe.

• Failed emissions test
• Rough idling or difficulty starting the car
• Heavy fuel odor
• Decreased fuel economy
• Engine stalling (rare)

What is the most common cause of a P0455 code?

The most common cause of this error code is a loose, broken, or missing gas cap. However, there are also other reasons why the code shows up in your car, like the following.

• A defective EVAP system hose
• Faulty evaporative emissions system
• Defective purge valve
• The fuel tank or fuel lines are leaking
• Defective fuel cap sensor
• Faulty fuel tank filler neck
• The fuel tank pressure sensor is damaged

How to fix code P0455

These are some common repairs you can do to fix engine code P0455.

• If found loose or broken, tighten or replace the gas cap.
• Replace defective or broken EVAP hoses or parts.
• Repair or replace the vent valve or purge valve if any fail diagnostics.
• If leaking, seal or replace the EVAP canister.

Can I drive with a P0455 code?

Technically, you can drive with this error code as it won’t impact your car’s safety or drivability. But we don’t recommend driving for a longer period with this code, as it can result in fuel vapors escaping. Eventually, your car will fail the emissions test. So, when diagnosed with this code, it is better to get it checked and repaired by a skilled technician.

Is a P0455 code expensive to fix?

No, the code isn’t that expensive to fix. The repair cost can start as low as $50 for a gas cap replacement to $700 for replacing the fuel filler neck or charcoal canister. Ideally, the cost will depend on the part that needs repair or replacement.

What happens if you ignore P0455?

Ignoring engine code P0455 can lead to your car failing the emissions test, decreased fuel economy, a strong fuel odor, and posing environmental and safety hazards.