Hyundai Sonata P0455 Code Diagnosis

The most frequent trouble code with the Hyundai Sonata The Code P0455. The trouble code refers to a number you receive when your Sonata is plugged into an OBDII scanner. If there's a P0455, it means that the problem is resolved. Large leak In the evaporative emissions control system. It is frequently found in conjunction with other codes such as P0420 or P0441.

Normally, P0455 does not pose a danger to the Sonata’s driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. It may also be accompanied with P0442. More information is available at Hyundai Sonata P0442 OBDII Cod.

Hyundai Sonata P0455 Definition

P0455 refers to a general OBDII trouble code. It means that no matter what make or model vehicle you have, this code will always mean the same (Sonata). 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 Hyundai Sonata’s EVAP system, it will throw the P0455 OBDII Code.

Hyundai Sonata P0455 OBDII Code Symptoms

The P0455 code is usually not accompanied with any other symptoms than those listed. Smells like 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 process deals with fuel vapors directly. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Sonata P0455 Trouble code Causes

The P0455 trouble code can be triggered in Hyundai Sonata by many factors. 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. A few clips are required to be found and removed.
• 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. 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. 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.

Hyundai Sonata Diagnosis - P0455

To diagnose the problem with your Hyundai Sonata'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.
• Once the mechanic has determined the trouble codes associated with P0455, he or she will usually Check out the EVAP System. These include the line and purge valve.
• 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 Hyundai Sonata, the actual leak will most likely still look rather small. The “large” really is referring to how much pressure is being lost.

P0455 is the most common fix

These are some of the most popular Sonata P0455 fix:

• 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 the gas cap.

You will need to solve the problem quickly. This information is hoped to be helpful. Please feel free to add anything below.

Are P0455 Serious Concerns?

While P0455 is not going to cause the Sonata’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. 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.