Ford F150 P0456: EVAP System – Small Leak

The most frequent trouble code with the Ford F150 Is the Code P0456. The trouble code refers to a number you receive when your F150 is plugged into an. OBDII scanner. A P0456 code indicates that there may be a slight leakage in the evaporative exhaust control system. This code is often found with or related to P0420,P0441 and, very rarely, P0440.

The P0456 issue is not usually a threat to your F150's driveability. 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 F150, it is actually referring to the amount of pressure lost, and not the physical size of the leak. They can also be very minor.

Ford F150 P0456

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 stands for:

System Leakage in the Smallest Detail – 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 F150’s EVAP system, it will throw the P0456 OBDII Code. If there is a large leak, it’ll throw P0455.

Ford F150 F0456 OBDII Symptoms

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

Particular attention should be paid to the smell of fuel near the fuel tank or fuel filler tube.

The EVAP process deals with fuel vapors directly. 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 F150's engine.

Trouble codes F150P0456

P0456 Trouble code can occur for many reasons in Ford F150. If your F150 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.

These are some of the most frequent problems that can throw off the code. They're listed in alphabetical order, from the most likely to the least.

• Hose of the 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. You should look for a hole or a tear in the code. This is the main problem that can cause the 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. There are some clips you will need to look for and then remove.
• Fuel Tank Sending Unit– It is possible for the gasket that attaches the fuel sending unit to the gas tank to go bad. It can lower the tank pressure, which could throw out 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. You may not get the message but a P0456. This will save you time and 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 F150 Diagnostics - P0456

The mechanic will have a lot of different tools at his disposal in order to determine the cause of P0456 on your Ford F150. These are some of the common diagnostics that can be done for the code

• A mechanic will often check for additional 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. Take a look at the EVAP system. It includes the purge valve and line as well as the canister.
• 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.
• Monitoring and checking the fuel tank pressure is a must.
• 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:

Most common P0456 fixes

Below are the top F150 P0456 fix:

• Replacement of gas cap
• Replacement for EVAP Line
• Replace charcoal canister
• Replacing 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 test your gas tank.

It's a good idea to try and figure out why your Ford F150 is throwing the code P0456. We trust this helped. You can add any additional information by leaving a comment.

Do you consider P0456 to be a serious concern?

While P0456 is not going to cause the F150’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. It is best to have it checked and treated immediately.

Please leave comments below if you have any suggestions. Thanks!