Chevy Sonic P0455 - EVAP System Large Lick Detected Diagnosis

The most frequent trouble code with the Chevy Sonic The P0455 Code. This code is a trouble code that refers to a number given to you by an OBDII scanner when your Sonic is plugged in. The trouble code P0455 indicates that there are a Leakage large It is part of the evaporative emission controller system. It is frequently found in conjunction with other codes such as P0420 or P0441.

P0455: System Gross Leak Evaporative Emission

The P0455 issue is not usually a threat to your Sonic's driveability. Certainly anytime the service engine soon light is on, it’s good to deal with it as soon as possible though. This is usually accompanied by P0442. More information is available at Chevy Sonic OBDII Code P0442.

Chevy Sonic P0455 Description

The universal OBDII code P0455 can be used to diagnose trouble codes. The code can be used regardless of the make and model of the vehicle. Technically the code is:

System Gross Leak Evaporative Emission System

The EVAP system collects fuel vapor from your fuel tank. It then sends it to the intake to ignite the engine in normal combustion. When there is a large leak in the Chevy Sonic’s EVAP system, it will throw the P0455 OBDII Code.

Chevy Sonic OBDII Codes for Chevy Sonic P0455

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 system is responsible for fuel vapors. If these vapors are leaking from the system, you’ll often smell them faintly while operating the vehicle.

Sonic P0455 Trouble code Causes

The P0455 code can be triggered by many factors in Chevy Sonic. These are some of the more common issues that can trigger the P0455 trouble code in your Chevy Sonic.

• Evap Hose– 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 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. 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.

Diagnoses- Chevy Sonic

To diagnose the problem with your Chevy Sonic's P0455, a mechanic can use a variety of tools. These are some of the common diagnostics that can be done for the code.

• A mechanic will usually check for any additional trouble 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 P0455. Check out the EVAP System. These include the line and purge valve.
• 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 Sonic, 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

Below are the top Sonic P0455 solutions:

• Replacement of 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 test your gas tank.

It's a good idea to try and figure out why your Chevy Sonic is throwing the P0455 code. This should help. Please feel free to add anything below.

Are P0455 Serious Concerns?

While P0455 is not going to cause the Sonic’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. Check your fuel level to make sure it is not leaked. It is best to have it checked and/or dealt with immediately.