P0456 CODE Evaporative (EVAP) Emission System Small Leak

P0456_CODE

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Whether you’re passionate about doing auto repairs or simply trying to maintain your own vehicle, understanding different codes is crucial. It will help you identify any problems with your vehicle so you can take proper action when possible.

Of course, there are times when you’ll have to take your car to a special technician. However, most of the time there are few things that you can do on your own to restore your vehicle’s performance to the most efficient level.

P0456 code means that there’s a small leak in your EVAP system. How does this affect the performance of your car? What causes it and what can be done to fix it? Read our article to find out the answers.


What Does P0456 Code Mean?

This code indicates that a small leak has been detected in the Evaporative Emissions System. It’s a generic code that appears if the engine fails the test two times in a row. This will prompt the engine control module or ECM to show the code.

EVAP systems are supposed to keep the fuel fumes in place so they don’t travel back into the atmosphere. When there’s a small leak in the system, this doesn’t happen. This means that the toxic fumes will leave their chamber and contaminate the air.


What Are the Symptoms of P0456 Code?

In most cases, a small leak that activates this code won’t have a lot of noticeable symptoms. This is because the EVAP system is a closed system that only manages the fuel tank vapors and has no effect on the performance of the engine.

A very slight fuel odor might be the easiest symptom to detect. However, if the leak is very small, you might never notice it although the fuel fumes will be traveling back into the air instead of staying trapped where they should be.

Another telltale sign is the malfunction indicator lamp or MIL. If it keeps on illuminating then it’s time to check your engine and all the adjacent parts, including the EVAP system to see if there are any leaks.

Another Troubleshooting Code about Evaporative EVAP Emission System Leak

P0455 CODE: Evaporative (EVAP) Emission System Large Leak


What Causes the P0456 Code?

Understanding what causes the code will help you solve the problem properly. Here are some reasons that might cause a P0456 code to appear.

  • There might be a leak in the hoses leading to or from the fuel tank.
  • The hoses of the EVAP system might be broken or cracked.
  • There might be a leak in the purge valve or the vent valve.
  • The EVAP canister might be leaking.
  • The gas cap vent might not fit properly so it doesn’t seal.

Common Mistakes When Dealing with P0456 Code

Even if you have some knowledge of auto repair, you might commit a few mistakes while dealing with P0456 code. Here are some mistakes that you should avoid.

  • Replacing the purge control valve without checking all the parts of the EVAP system. Some people believe that the purge control valve is the culprit when it might be a small leak that they missed.
  • Failure to inspect all hoses connected to the fuel tank and replacing unnecessary parts that don’t solve the problem.
  • Replacing the gas cap with another one that doesn’t fit properly.

Is it Safe to Drive with the P0456 Code?

You should know that this code doesn’t affect the performance of the engine. This means that you can drive the car with the P0456 code. However, this won’t be completely safe.

The code indicates that there’s a leak that lets the toxic fumes escape into the air causing air pollution every time you fill the tank with fuel. The toxic fumes will travel back into the air even if you’re not running the car.



How to Fix P0456 Code?

After fully examining the vehicle, you’ll be able to determine the right and most suitable solution that will help you fix the problem. Here are some solutions that will clear the code.

  • Replace the leaking gas cap. You should make sure that you’ve purchased and installed an original part because using one from another brand might be the cause of the problem.
  • Check out the purge vent valve. If it’s broken or clogged, you’ll need to replace it.
  • Examine the purge control valve. If it’s leaking, then it should be replaced promptly.

This code isn’t very common but you might encounter it while checking your vehicle. If you’re unable to detect the problem, then you should probably seek the help of a professional mechanic. Trained mechanics will have enough tools that enable them to detect the real cause of the problem and determine the best way to fix it.



About the Author JamesL Davis

James is a certified auto technician specializing in commercial vehicles. With 30 years of experience under his belt, James has encountered almost every type of automotive issue there is! Besides his day job at the repair shop, he is also an amateur race car driver.

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