Chevy Equinox P0455, EVAP System Large-Leak Diagnosis

The most frequent trouble code with the Chevy Equinox The Code P0455. This code is used to refer to the number given when Equinox is connected to an OBDII scanner. The P0455 code indicates that the Equinox is experiencing trouble. Large leak It is part of the evaporative emission controller system. This code is often found with or related to P0420,P0441 and, very frequently, P0440.

P0455: System Gross Leak Evaporative Emission

Your Equinox is usually not at risk from P0455. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. It's often associated with P0442. More information is available at Chevy Equinox OBDII Code P0442.

Chevy Equinox P0455 Definition

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 always mean the same (Equinox). Technically, the code stands for:

System Gross Leak Evaporative Emission System

The EVAP captures any fuel vapor in the fuel tank. They are then sent to the engines intake for ignition. When there is a large leak in the Chevy Equinox’s EVAP system, it will throw the P0455 OBDII Code.

Chevy Equinox OBDII code Symptoms

A P0455 Code will usually not cause any symptoms except the ones listed below. Smells like gas And 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 process deals with fuel vapors directly. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Equinox P0455 Trouble Code Causes

Many things can trigger the P0455 Trouble Code in Chevy Equinox. The most frequent problems that trigger this code are:

• Hose for Evap System– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. This can lead to the P0455 code. 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 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.
• 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 could cause a drop in tank pressure or throw 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 P0455. 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.

P0455 Diagnoses- Chevy Equinox

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Chevy Equinox P0455. These are some of the common diagnostics that can be done for the code

• A mechanic will often 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.
• Once the mechanic has determined the trouble codes associated with P0455, he or she will usually Check out 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 Chevy Equinox, 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 Equinox P0455 solutions:

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

You should start with the gas caps and move on to the fuel tanks. This is because the gas caps are the easiest to replace and the least costly.

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

We wish you all the best in finding out why your Chevy Equinox is throwing the P0455 code. 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 Equinox’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 treated immediately.