Chevy Malibu, P0455: Large Leak Diagnosed by EVAP
This is one of the most commonly encountered trouble codes for the Chevy Malibu The Code P0455. This code is used to refer to the number given when you connect your Malibu to an OBDII scanner. The trouble code P0455 indicates that there are a 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 Malibu's driveability is generally not affected by 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. For more information, see Chevy Malibu OBDII code P0442.
Chevy Malibu P0455 Definition
The universal OBDII code P0455 refers to trouble codes. It means that no matter what make or model vehicle you have, this code will always mean the same (Malibu and not). 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 Chevy Malibu’s EVAP system, it will throw the P0455 OBDII Code.
Chevy Malibu P0455 OBDII Code Symptoms
The P0455 code is usually not accompanied with any other symptoms than those listed. The smell of 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 system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.
Malibu P0455 Trouble Code Causes
Many things can trigger the P0455 code in Chevy Malibu. These are some of the more common issues that can trigger the code.
- 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. You should look for a hole or a tear in the code. 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.
- 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. 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. 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.
P0455 Chevy Malibu Diagnosis
The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Chevy Malibu P0455. 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. 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 P0455. Check out the EVAP System. It includes the purge valve and line as well as the canister.
- A mechanic will examine the gas cap and verify that it is able to withstand high pressure. 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 Malibu, 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
These are some of the more common Malibu P0455 solutions:
- Replacing the gas cap
- Replacing EVAP lines
- 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 Malibu is throwing the P0455 code. This should help. You can add any additional information by leaving a comment.
Are P0455 Serious Concerns?
While P0455 is not going to cause the Malibu’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/or dealt with immediately.