Ford Fusion P0455: EVAP System → Leak Detected (Large)

The most frequent trouble code with the Ford Fusion The Code P0455. The trouble code refers to a number you receive when your Fusion is plugged into an OBD2 scanner. It has to do the emission system. The P0455 code indicates that the emission system is malfunctioning. Large leak In the evaporative emissions control system (EVAP). It is frequently found alongside, or closely related to, other codes like P0420/P0430/P0441 and most often, P0440.

P0455: EVAP System → Leak Detected (Large)

Your Fusion is usually safe from P0455. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though.

Ford Fusion Definition P0455

The universal OBDII code P0455 can be used to diagnose trouble codes. It means that no matter what make or model vehicle you have, this code will still mean Fusion. Technically, the code stands for:

System Gross Leak Evaporative Emission System

The EVAP captures any fuel vapor in the fuel tank, and transmits them to engines intake for ignition. When there is a large leak in the Ford Fusion’s EVAP system, it will throw the P0455 OBDII Code.

Ford Fusion OBDII Code Symptoms

A P0455 Code will usually not cause any symptoms except the ones listed below. The smell of gas And the service engine soon light. The slightest drop in fuel economy may also be noticeable.

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

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.

Fusion P0455 Troublecode Causes

Many things can trigger the P0455 code in Ford Fusion. The most frequent problems that trigger this code are:

• 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 P0455 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 P0455 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips.
• A Faulty Canister of Charcoal– The charcoal canister is often the cause of P0455.
• 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. It may be worth your time to get that message and a P0455 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. It is possible for this gasket to dry, particularly if vehicles spend a lot of time in dry environments. When it dries out, the fuel tank can’t hold pressure anymore.

Ford Fusion Diagnostics - P0455

To diagnose the problem with your Ford Fusion's P0455, a mechanic can use a variety of tools. These are some of the common diagnostics that can be done for the code

• The mechanic will check for other codes. It is easier to diagnose problems if there are more codes. 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 P0455. 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.
• Monitor and check the pressure in your fuel tank.
• Following the inspections and repairs, the mechanic will conduct two more tests.
• 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:

While the trouble code may state that there is a “large leak” in the EVAP system of your Ford Fusion, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

Most common P0455 fixes

Below are the top Fusion P0455 solutions:

• Replacement of gas cap
• Replacing EVAP lines
• 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 test your gas tank.

You will need to find the root cause of your Ford Fusion throwing the code P0455. We trust this helped. Please feel free to add anything below.

Are P0455 Serious Concerns?

While P0455 is not going to cause the Fusion’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. Check your tank regularly to make sure there is no fuel leaking. It is best to have it checked and/or dealt with immediately.