We Buy All Cars, Running or Not!

How to Fix P0456 Code: “EVAP Control System Leak Detected (Very Small Leak)”

How to Fix P0456 Code

If you're searching for how to fix the P0456 code, confirm that the error code exists using an OBDII scanner. Once the P0456 error code is confirmed, try checking the gas cap and replacing it if necessary. If this didn't work, inspect the canister purge valve and replace it if there are any signs of damages. After fixing the issue, you should use an OBDII scanner to clear out the code. If none of the listed methods resoved your P0456 code, take the vehicle to the nearest repair shop for specific manufacturer inspections. 

⚠️ If It's Broken, Don't Fix It - Get Paid Cash for Your Vehicle ⚠️

The P0456 error code is very common in the most vehicle, and it basically indicates an issue with the EVAP control system where the internal computer detected a small leak.

Since the EVAP system needs to work properly all the time to prevent any carbonate vapors from reaching the environment, dealing with a P0456 code is essential, and you have to resolve the problem as soon as possible to prevent harming the environment and to make sure that your vehicle passes the emission test.

This article provides all you need to know about the P0456 error code. We highlight the primary role of the EVAP system, the main causes, and symptoms of the P0456 code, and the expected repair options and repair costs to get rid of the P0456 code. 

What is the P0456 code definition?

The primary definition for the P0456 is “EVAP Control System Leak Detected (Very Small Leak).” In the following section, we will give you a better idea about the purpose of the EVAP system in your vehicle. 

How does the EVAP system trigger a P0456 code? 

Since the error code P0456 is linked to the EVAP system, it is crucial for you as a driver to understand how the system works and what exactly it means to detect any leaks in the system.

In 1970, California required every vehicle to add an EVAP system responsible for detecting and capturing any hydrocarbon vapors. This system aims to ensure that these vapors do not escape the atmosphere and prevent harming the environment. Modern cars are equipped with more advanced EV AP systems that can capture and detect any leaks at around as small as 0.02 inches!

Once any leak is detected, the EVAP system will signal to the vehicle's internal computer. Once the computer receives this signal, it triggers the check engine light, and once you scan the computer, error code, P0456 will be displayed on the screen. 

What are the primary causes for the P0456 code?

There are plenty of reasons that might trigger a P0456 code, including:

  • Issues with the damaged fuel cap
  • Problems with loss or missing fuel cap 
  • Troubles with disconnected hoses in the EVAP system
  • Malfunction in the purge volume control valve
  • Damage is in that canister vent control valve
  • Issues with the fuel tank leaks 

How do I know if it’s the P0456 code? Symptoms of the P0456 code

As a driver, you should keep in line for any symptoms indicating a P0456 code. By detecting this error code early, you can prevent major damages and significant complications that might cost you thousands of dollars down the road.

Based on our experience, there are a variety of symptoms you might notice when the P0456 code is triggered, including

  • Obviously, check engine light illuminating
  • Increase in the vehicle’s emissions
  • A fuel like the smell
  • A reduction in the vehicle's fuel economy 

How to fix the P0456 code?

Luckily, there are some reports by many automotive experts to help you get rid of the P0456 code at home without needing a professional mechanic. You don't have to worry about labor costs, especially if you're dealing with extremely high labor costs at dealerships of common automakers.

Let's take a closer look below at some of the common DIY's you can follow to get rid of the P0456 code: 

  • Check if it's really a P0456 code 

Before we list the different DIYs to help you fix a P0456 code, it is very important to ensure that the code exists in the 1st place. You can use a simple OBD scanner to connect to the vehicle's computer and scan any current errors.

If the code exists, you'll see on the screen of the scanner a P0456 code along with a short text definition of this code. If you don't have the required mechanical skill sets, sometimes reading the text definition of any error code will not be very intuitive, and that's where this article comes in handy to help you understand this code and give you some idea about how to fix it.

  • Check the fuel cap 

The most common cause for triggering the P0456 code issues with the fuel cap. Carefully open the fuel cap and inspect it for any damages. Then, use a WD40 clear and spray it around the fuel cap. 

Also, consider cleaning the fuel tank outside right under the fuel cap to ensure no debris or contaminations. Using a dry cloth, wipe out the fuel cap had the fuel tank opening. 

Reinstall the fuel cap and check if the problem was resolved or not. If the problem wasn't resolved, take a look at the fuel cap and see if it's damaged or has any signs requiring the group to release it. Refer to your vehicle's owner’s manual and check the same model year, and type for this fuel cap so you can purchase the right one and install it. 

  • Inspected the canister purge valve 

If the fuel cap was in good condition, your next step is to look at the canister purge valve. It is usually located next to the intake, close to the throttle body. If you had a hard time locating the canister purge valve, you could always refer to your vehicle's owner’s manual to get accurate guidance.

To inspect the canister purge valve, you don't have to remove it, and you should perform the inspection while the engine is running. Put your finger on the canister valve small tube and see if there is any sign of sucking. If that's the case, the canister valve is stuck and requires replacement. 

It's very important to make sure that you compare the old valve to the new one or refer to your manual to get the right number to prevent purchasing the wrong one. Simply remove the old canister valve and install the new one.

Check if the P0456 error code is still there or not. 

  • Clear the P0456 error code 

When the check engine light illuminates due to an error code, do not expect that this error code will be deleted by itself. You must use an OBDII scanner and connected it to the vehicle's computer to clear the codes. After clearing the codes, it is recommended that you perform a second scan to make sure that the code is not there anymore.

  • Visit a professional mechanic 

 If none of the mentioned methods worked for you and the P0456 error code is still there, unfortunately, your only one solution now is to take your vehicle to a repair shop where the professional mechanic performs certain manufacturer inspections to detect the actual root culprit. 

Can I drive my car with a P0456 code?

Although the P0456 code is not life-threatening, it is never recommended to ignore any internal error codes for a long time. Probably you'll be able to drive this car for a couple of miles and maybe thousands of miles, leaving the problem for a very long time can result in major complications down the road.

Keep in mind that if you were planning to perform an emission test, your vehicle will most likely not pass the emission test when it has a P0456 code.

The other thing to consider is the impact of this error code on the environment. Remember that the EVAP system is responsible for preventing any fuel vapors from getting to the environment and harming it. By allowing the EVAP system to release some of these vapors, you affect the health of the environment and the people around you. Thus, you'd better take care of this error as soon as possible. 

How much does it cost to resolve the P0456 code?

Repair costs to fix a P0456 code differ significantly depending on the primary root of the problem. For example, if your problem is related to a damaged fuel cap, repair costs range from $20 to $60.00.

On the other hand, if the problem arises from an issue with the EVAP purge of the volume control valve, repair costs might range from $150 to $200. When the EVAP line itself is damaged, you can replace it for somewhere between $50 and $100. Finally, if the canister charcoal is damaged, repair costs might range from $200 to $600.

Keep in mind that all mentioned ranges do not include labor costs, which might differ significantly depending on the location where you get that done.

While many drivers might prefer to go to a small repair shop there to save on labor costs, many owners of modern vehicles prefer to visit the dealership because they confirmed that experienced mechanics could handle their issue. Hence, there is very little chance to introduced major damages to my mistakes.

Will code P0456 clear itself? 

As we indicated in the DIY section, any internal code will not clear itself unless you ask your vehicle to do it. You can always use an OBDII scanner and ask it to clear out any inactive errors once you resolve the issue. 

The other thing to keep in mind is rescanning the vehicle's computer after resolving the issue. Even if you could fix the P0456 code successfully, you should request a second scan by the OBDII scanner to confirm that the problem was gone completely. 

How long can you drive with an EVAP leak? 

Based on our experience, there is no set threshold for how long you can drive with an EVAP leak. It's just you must keep an eye for any other major symptoms indicating significant complications. If there is nothing wrong, your vehicle will still move.

Keep in mind that with an EVAB leak, and even if it's very small, your vehicle won't be able to pass the emission test. 


The P0456 code indicates a problem with the EVAP system, and your car no longer traps any harmful vapors from the fuel system. 

As a driver, you need to be aware of the potential causes and symptoms of a P0456 code. This article highlighted all this information and provided you with some simple two DIY's to help you fix the P0456 code at home without needing a professional mechanic.

If you could not resolve the issue successfully using dimension DIY's, the only one option is to take your car to the repair shop. Personal mechanics should perform certain manufacturer inspections that are usually based on the vehicle's brand and model year. Using these tests, mechanics will confirm the primary cause of triggering the P0456 code if it's not mentioned in this article. 

We always like to remind our customers that if repair costs reach a very high threshold, it might be the right time now to get rid of this car and use the payment toward a better car. 

Cash Cars Buyer is one of the top-rated car removal companies in the nation that guarantees to pay you the top dollars and will provide you with free towing despite your living location around the United States. 

The best thing about Cash Cars Buyer is that our process is very straightforward and doesn't take more than a couple of days to get your vehicle removed safely and for the most money. 

To learn more about our process and our team, you can reach out to us by giving us a call at 866-924-4608 or visit our home page click on the free instant online offer.

© 2022 Cash Cars Buyer. All Rights Reserved. Terms & Conditions | Privacy Policy | Sitemap