How To Fix P0455 Code?

When you notice that your check engine light has suddenly illuminated, you insert your scan tool into the OBD-II port to determine the source of the problem and you discover that the p0455 code has been saved. You begin to check your vehicle for leaks and discover that there are none. This post will explain how to locate a leak and how to repair it.

The EVAP emission system is a sealed fuel gas system that runs through your car engine for environmental reasons. If the engine control unit detects a leak there, a p0455 code will be stored.

What Causes P0455 Code?


P0455 code is an OBD-II fault code that indicates that the engine computer has identified a major leak in the engine’s Evaporative Emissions Control (EVAP) system. The EVAP system keeps fuel vapors from escaping into the environment.

The most common cause of a p0455 code is that it can be caused by various factors such as driving with a loose or damaged fuel cap or other factors such as
1. Defective control valves.
2. A broken gas cap.
3. There is a leak in the charcoal canister.
4. EVAP hoses that are leaking.
5. Fuel tank leaks

Symptoms Caused Due To Fault Code


A P0455 problem code will usually illuminate the check engine light and have a strong odor while driving the vehicle, some of the symptoms include:-

1. The Check Engine Light is illuminated, depending on the make of your car.
2. A modest decrease in fuel economy.
3. The odor of gasoline
4. Frequently used with error codes: EVAP- codes P0440 and P0441

How To Diagnose Fault In EVAP System?

Before Working on the vehicle inspection is important, so check the vehicle properly and then proceed with the repairs.

1. Plug in your OBD2 Scanner and look for issue codes. Check that the fault code is not accidentally saved after refueling.
2. Check that the gas cap is tight and that the seals are in good condition.
3. Examine the EVAP wiring harness
4. Examine the fuse and relays

How To Fix The Fault Code?

Because code P0455 might occur for a variety of causes, the only method to resolve the issue is to identify the components that are causing the problem and repair or replace them. If your gas cap was left open, close it and see if that solves the problem. For some, replacing the gas cap is the only option. If replacing the gas cap does not solve the problem, repairing damaged EVAP system tubes and hoses may be the solution.

Fixing/Replacing EVAP System-

We will suggest you for reaching out to professionals, for getting a quality job as it is one of the most hectic to do check and replace the EVAP System otherwise we will mention how to do it as easily as possible.

Finding Leaks-

It is one of the time-consuming parts of the job to find the leak it can be anywhere of any size, we are giving some ways to find the leak easy which won’t cause you headache to fix p0455 code


1. Vacuum Test

Because EVAP systems connect to the intake manifold, an engine vacuum gauge can be used to check the integrity of valves and lines. Check for vacuum in the EVAP system while the engine is running and the purge valve solenoid electrical contact is unplugged. There should be none. The presence of an engine vacuum indicates that the purge valve is jammed open.

2. Smoke Test-

It is one of the best methods used for finding leaks it works on the principle, startup the vehicle if the suspected area sucks the smoke it is the area which is needed to be fixed

Replacing Parts-

Sometimes it can be just fixed by tightening the fuel caps which is most efficient for everyone otherwise you can replace or repair parts

1. Replacing Fuel Cap-

Fuel cap

It is one of the inexpensive replacements you can try, after running for several thousand miles and being on/off from the system and may start to show wear and tear, and may cause leaks it is better to replace the fuel cap and the problem may be solved after that

2. Replacing Hoses-

Sometimes hoses get torn out over time which also creates a leak in the system which can be replaced


3. EVAP Replacement-

The EVAP System can be checked and replaced for parts like- Canister, Fuel Tanks which should be verified by professionals only

Does It Affect Vehicle Performance?


Yes! It does Fuel vapor leaks may cause problems with fuel economy. As a result, P0455, like other diagnostic trouble codes, should be resolved as soon as possible to avoid potential fuel mileage issues and other challenges involving the emission control system and other vehicle components. Because of the leak, your engine may run somewhat leaner than usual affecting its overall performance

Cost For Repairing The Fault Code-

A diagnostic cost of roughly $100 is frequently charged by shops. In contrast to minor leaks, which may require more investigation, a large leak is usually discovered fast. A lost gas cap might cost you $25. However, depending on the availability of parts, changing a vent valve or purge valve can cost between $200 and $300. A charcoal canister repair will cost between $400 and $600, depending on where you live. A filler neck replacement might cost between $300 and $400.


Most of the time, nothing major happens when the p0455 code is activated. Although the Check Engine Light may illuminate, additional symptoms are exceedingly uncommon. Most people keep driving, ignorant of the idea that something is wrong. We advise you to have your vehicle assessed and fixed. The leak of the evaporative emission control system does not only pollute the air while the car is running. A pinprick-sized hole can emit harmful evaporative emissions into the atmosphere 24 hours a day, seven days a week. This is why, after ruling out a gas cap issue, you should visit a certified mechanic if you have a p0455 engine code.

Leave a Comment