Honda Civic P0457: EVAP System – Leak Detected

P0457 This is an example of a common problem code for the Honda Civic. The code refers to the number you get when you plug in your Civic. OBDII scanner. The P0457 signifies that the Evaporative Emissions Control (EVAPS) system is leaking. This is similar to P0455, which indicates a large leak, and P0456 that indicate a small leak.

The P0457 problem is not usually a threat to your Civic's driveability. Certainly anytime the service engine soon light is on though, it’s good to deal with it as soon as possible.

Honda Civic P0457 Description

The universal OBDII code P0457 refers to trouble codes. The code can be used regardless of the make and model of the vehicle. Technically, the code stands for:

System 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 leak in the Honda Civic’s EVAP system, it will throw the P0457 OBDII Code.

Honda Civic OBDII Code Symptoms

The P0457 code is usually not accompanied with any other symptoms than those listed. The smell of gas And the service engine soon light.

Particular attention should be paid to the smell of fuel near the fuel tank or fuel filler tube.

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. But, it won’t affect the way the engine itself runs. The EVAP technology deals only with the fuel vapor but not how the engine runs in the Civic.

Civic P0457 Trouble Code Causes

P0457 can be triggered by many factors in Honda Civic. If your Civic has warned you at all in the last few months that the fuel cap was off when it wasn’t, then replacing it would be a great first step.

Below are the top most probable problems that could throw the code. These were listed alphabetically, in some order.

• Hose for Evap System– The hose that carries the fuel vapor from the fuel tank to the intake manifold can begin to leak. The P0457 error code will be generated. You should look for a hole or a tear in the code. This is the main problem that can cause the code.
• Vapor Canister Purge Valve– One of the most common causes of the P0457 code is the vapor canister purge valve. It’s really easy to replace. You will need to locate and take out a few clips.
• 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 P0457. 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. 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.

P0457 Diagnosis- Honda Civic

The mechanic will have a lot of different tools at his disposal in order to determine the cause of your Honda Civic P0457. The most commonly used methods to diagnose this code are:

• The mechanic will check the engine to determine if any trouble codes are present. 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 P0457. Check out the EVAP System. It includes the line, purge valve and 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:

The Most Popular P0457 Fixes

These are some of the most popular Civic P0457 repairs:

• 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.

You will need to solve the problem quickly. We trust this helped. You can add any additional information by leaving a comment.

Do you consider P0457 to be a serious concern?

While P0457 is not going to cause the Civic’s engine to stop running, it should not be treated lightly. Fuel leaks could be a problem. Check your tank regularly to make sure there is no fuel leaking. You should immediately take it in for repair or replacement.

Please leave comments below if you have any suggestions. Thanks!