P0457 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

This code means evaporative emission control (EVAP) system leak detected. The gas in a car’s fuel tank and lines will gradually evaporate over a period of time. The government regulates the amount of evaporative emissions in new vehicles. So, carmakers are required to have the system installed.

The EVAP systems store and dispose of vapors before they make it into the atmosphere. You will see the code P0457 when the system detects fuel vapors leaking. 

MEANING

EVAP systems help prevent fuel vapor leakage into the atmosphere. Twenty percent of hydrocarbon car emissions are from fuel evaporations. The emissions are harmful compounds that contribute to air pollution. The systems are designed to keep them from leaking and harming the environment.

You will see one or more of the codes P0455, P0456 and P0457 if there is a leak in the system. Once detected, the power-train module stores the code.

The codes P0455, P0456 and P0457 are similar in that they will be triggered when there is a vacuum leak. The difference is that they indicate the severity of the leak present. A P0455 leak will refer to a less severe leak, and the P0457 trouble code indicates that there is a very severe leak.

Causes

There are a few different reasons why the P0457 trouble code might appear. The gas cap may be a reason why a car’s EVAP systems are detecting a leak. The most common reason for the P0457 code is having a loose gas cap. A loose cap can allow the vapors to enter the system. A cracked or missing gas cap can also result in the code.

A problematic hose or vacuum canister are other possible reasons for a leak. Cracks or a rotting hose will allow for fumes to escape. And a cracked vacuum canister can also be the cause of vapor leaks.

Symptoms

In the case of an emissions leak, the Check Engine Light will be illuminated. A leak will typically not change the performance or drivability of a vehicle. However, if the fuel leak is severe enough, it will decrease the car’s fuel efficiency.

Diagnosis

The P0457 code generally does not present symptoms aside from the Check Engine Light. Because of this, it may be necessary to have a mechanic take a closer look to determine what the problem is. A mechanic can use an OBD-II scanner. This can detect the specific code that caused the light to illuminate.

After identifying the P0457 code, an inspection can begin. The gas cap can be visually inspected first. It can be checked to see if it is missing, not secure or cracked. A mechanic can also check for foreign objects that may be preventing a secure seal. The gas cap may need to be replaced, and then the mechanic can clear the code and test it again. If the gas cap is not the issue, the other EVAP system components can be inspected for problems.

Common mistakes

More often than not, vehicle owners believe that an EVAP system component needs replacing when the Check Engine Light turns on. However, that may not be the case. The problem may simply be due to the gas cap not being properly tightened.

How serious is this?

There are three codes related to the EVAP system; they are the P0455, P0456 and P0457. The P0457 is the most severe code you can receive related to leaks in the EVAP system. The leak can decrease the fuel economy and cause the car’s amount of fuel emissions to rise.

It is possible to have greater fuel leaks in the future depending on the current emission problem. This can result in the need for more expensive repairs. It could also cripple the car until the problem is addressed.

What repairs can fix the code?

A number of repairs can fix the P0457 code. One or more of the EVAP system’s vacuum hoses may need to be replaced. The intake manifold fitting can also be checked to ensure it is sealed and crack-free. If it is damaged, it needs to be replaced. Finally, if the charcoal canister shows any sign of cracking, it will need replacing. 

Related codes

Some related codes include P0455 and P0456.

Conclusion

The P0457 code is the most severe of the EVAP system leaks. It usually does not alter a car’s drivability or performance much. However, it can lead to more serious issues further down the road if it is not addressed.

Fortunately, checking the gas cap can take care of the majority of issues. Or a visit to the mechanic can help you identify the problem and necessary repairs.