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

The most frequent trouble code with the Ford Ranger Is the Code P0455. The trouble code refers to a number you receive when your Ranger is plugged into an OBD2 scanner. It has to do the emission system. The trouble code P0455 indicates that the emissions system is malfunctioning. Leakage large In the evaporative emissions control system (EVAP). This code is often found with or related to other codes such as P0420 and P0430.

P0455: EVAP System → Leak Detected (Large)

The P0455 issue is not usually a threat to your Ranger's driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though.

Ford Ranger P0455 Definition

P0455 refers to a general OBDII trouble code. It means that no matter what make or model vehicle you have, this code can mean the exact same thing. Technically speaking, it stands for:

System Gross Leak 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 large leak in the Ford Ranger’s EVAP system, it will throw the P0455 OBDII Code.

Ford Ranger P0455 OBDII Code Symptoms

The P0455 code is usually not accompanied with any other symptoms than those listed. The smell of gas The service engine soon light. The slightest drop in fuel economy may also be noticeable.

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.

Ranger P0455 Troublecode Causes

P0455 code can be triggered by many factors in Ford Ranger. These are some of the more common issues that can trigger the P0455 trouble code in your Ford Ranger:

• Evap Hose– 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. It should be checked for tears or holes. This is one of most frequent causes for 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. There are some clips you will need to look for and then remove.
• The Faulty Charcoal Caister– 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. 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 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. 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 Ranger P0455 Diagnostics

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Ford Ranger P0455. The most commonly used methods to diagnose this code are:

• The mechanic will usually 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.
• Once the mechanic has determined the trouble codes associated with P0455, he or she will usually 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.
• 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:

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

The Most Popular P0455 Fixes

Below are the top Ranger P0455 fix options:

• 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.

You will need to be patient when trying to figure out why your Ford Ranger is throwing the code P0455. This should help. Please feel free to add anything below.

Do you consider P0455 to be a serious concern?

While P0455 is not going to cause the Ranger’s engine to stop running, it should not be treated lightly. There could be fuel contamination. You should pay extra attention to the level of your fuel tank and ensure that you're not leaking fuel. You should immediately take it in for repair or replacement.