Ford Explorer P0456: EVAP System – Small Leak

This is one of the most commonly encountered trouble codes for the Ford Explorer Is the Code P0456. The trouble code refers to a number you receive when your Explorer is plugged into an a OBDII scanner. The code P0456 indicates that the evaporative emissions control system has a tiny leak. This code is often found with or related to P0420,P0441 and, very rarely, P0440.

Your Explorer's driveability is generally not affected by P0456. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible.

While the trouble code may state that there is a “small leak” in the EVAP system of your Ford Explorer, it is actually referring to the amount of pressure lost, and not the physical size of the leak. They can also be very tiny.

Ford Explorer P0456 Definition

P0456 stands for a universal OBDII Trouble Code. The code can be used regardless of the make and model of the vehicle. Technically the code is:

System Leakage of Small Size – Evaporative Emission System

The EVAP system collects fuel vapor from fuel tanks and then sends it to the intake to ignite the engine in normal combustion. When there is a small leak in the Ford Explorer’s EVAP system, it will throw the P0456 OBDII Code. If there is a large leak, it’ll throw P0455.

Ford Explorer P0456 OBDII Code Symptoms

A P0456 Code will not usually be associated with other noticeable symptoms. The smell of gas And the service engine soon light.

The fuel tank and fuel filler tubes should smell particularly strong.

The EVAP system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle. But, it won’t affect the way the engine itself runs. The EVAP system is for fuel vapor and does not affect the operation of your Explorer's engine.

Explorer P0456 Trouble Code Causes

P0456 can be triggered by many factors in your Ford Explorer. If your Explorer has warned you at all in the last few months that the fuel cap was off when it wasn’t, then replacing it would be a great first step.

Below are some common issues that could throw code. These problems were listed alphabetically, most to least probable.

• Hose for Evap System– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. The P0456 error code will be generated. It should be checked for tears or holes. This is the leading cause of code.
• Vapor Canister Purge Valve– One of the most common causes of the P0456 code is the vapor canister purge valve. It’s really easy to replace. You'll need to identify and remove a few clips.
• Fuel Tank Sending Unit– It is possible for the gasket that attaches the fuel sending unit to the gas tank to go bad. This could cause a drop in tank pressure which can throw off the code.
• Fuel Cap– A bad fuel cap can cause the code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. It may be worth your time to get that message and a P0456 to ensure you don't waste any money.
• Fuel Filler Neck– There is often a gasket where the fuel filler neck connects with the gas tank. The gasket may dry out especially if the vehicle is in dry conditions. When it dries out, the fuel tank can’t hold pressure anymore.

Ford Explorer Diagnostics - P0456

To diagnose the problem with your Ford Explorer's P0456, a mechanic can use a variety of tools. These are some of the common diagnostics that can be done for the code

• Most mechanics will check for any additional trouble codes. A mechanic will usually check for additional trouble codes to help diagnose the problem. That’s because when they appear together in certain combinations, there will often only be only a few conditions that will throw any combination of codes at one time.
• The mechanic will normally determine what trouble codes are associated with P0456. Check out the EVAP System. These include the line and purge valve.
• To ensure that the cap can withstand pressure, the mechanic will check it. If you are getting a warning that your gas cap is off, even when it’s on, replacing it will more than likely clear this code.
• Monitor and check the pressure in your fuel tank.
• The mechanic will then perform the following tests after completing the above-mentioned checks:
• A smoke test, and they’ll use a scan tool to confirm that the EVAP solenoids and valves are operating properly.

Here’s a pretty good video on diagnosing these leaks from Scotty Kilmer, if you are interested:

This is the most common P0456 fix

These are some of the most popular Explorer P0456 fixes.

• Replacing the gas cap
• Replacement for EVAP Line
• Replace charcoal canister
• Change the fuel tank

It is best to begin with the gas cap, and then work your way up to the fuel tanks. The gas cap is the most difficult and cost-effective item to replace.

Here’s a great video on How to check your gas cap.

It's a good idea to try and figure out why your Ford Explorer is throwing the P0456 error code. This information should be helpful. Please feel free to add anything below.

Are P0456 Serious Concerns?

While P0456 is not going to cause the Explorer’s engine to stop running, it should not be treated lightly. There could be fuel contamination. Check your tank regularly to make sure there is no fuel leaking. You should immediately take it in for repair or replacement.

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