Ford Ranger P0456: EVAP System – Small Leak

The most frequent trouble code with the Ford Ranger Is the Code P0456. The trouble code refers to a number you receive when your Ranger is plugged into an a OBDII scanner. A P0456 code indicates that there may be a slight leakage in the evaporative exhaust control system. It is sometimes found along with other codes such as P0441 or P0420.

The P0456 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.

While the trouble code may state that there is a “small leak” in the EVAP system of your Ford Ranger, it is actually referring to the amount of pressure lost, and not the physical size of the leak. This can happen in very small amounts.

Ford Ranger P0456 Definition

The universal OBDII code P0456 can be used to diagnose trouble codes. 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 Ranger’s EVAP system, it will throw the P0456 OBDII Code. If there is a large leak, it’ll throw P0455.

Ford Ranger P0456 OBDII Code Symptoms

The P0456 code is usually not accompanied with any other symptoms than those listed. Smells like 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 Ranger's engine.

Ranger P0456 Trouble code Causes

P0456 can be triggered by many factors in your Ford Ranger. If your Ranger 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.

• Evap Hose– 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. 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. 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. 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. 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 Ranger P0456 Diagnostics

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

• The mechanic will check to make sure there are no 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 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.
• 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:

The Most Popular P0456 Fixes

These are some of the more common Ranger P0456 solutions:

• Replacing the gas cap
• Replacing EVAP lines
• 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 check your gas cap.

You will need to be patient when trying to figure out why your Ford Ranger is throwing the code P0456. We trust this helped. Please feel free to add anything below.

Do you consider P0456 to be a serious concern?

While P0456 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. It is best to have it checked and/or dealt with immediately.

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