P0457 Error Codes: Meaning, Causes, Symptoms, Diagnosis, and Fixes

P0457 is a generic code that does not identify the actual cause of the problem. The most common cause of P0457 is a vacuum leak in the Evaporative Emission Control System. This may stem from an air filter, hose, or valve failure and comes to notice through the illumination of check engine light on your vehicle’s dashboard.

But you need not worry as all the causes of check engine light are not that severe. A typical example of a less severe cause of a check engine light is error code P0457.

You can fix this code by cleaning or re-tightening a loose gas cap without spending money on a costly repair. Or, it may be time to replace these parts and get back up and running again.

Read on to learn what the P0457 fault code means, probable causes, and symptoms. This article will also explain the diagnostics and repair procedures needed to fix the problem.

Code P0457 Definition

P0457 error code means that the powertrain control module [PCM] has detected a leak in the evaporative emission control [EVAP] system. The car computer can register P0455 and P0457 at the same time since both show a system leak. 

fault code p0457

What Does P0457 Mean?

The evaporative emission control [EVAP] system prevents gas vapor from escaping into the surrounding air and causing pollution. If a vacuum leak occurs, the powertrain control module [PCM) or engine control unit [ECU] will detect it and log error codes P0455, P0456, or P0457.

These codes mean gas vapor leaks in the evaporative emission control system. However, they differ on the severity of the leaks. The P0455 represents a significant leak on the EVAP system; the P0456 represents a small leak. In contrast, the P0457 refers to a leak (it could be small or large) on the EVAP system.

It’s essential to note that the P0457 is a generic diagnostics trouble code specified by the Society of Automotive Engineers [SAE]. The code definition may vary depending on the automakers.

What Are the Symptoms of Code P0457?

Because of the design of the evaporative emission control [EVAP] system, you’ll not notice any adverse effects when the functionality is altered. While P0457 on Jeep Wrangler may project the same sign or causes with P0457 on Subaru Forester, a vehicle ECU may not log the code on other vehicles.

However, here are a few signs a vehicle with a logged diagnostics trouble code P0457 may project;

  • Gas smell
  • Engine warning light
  • Increase in fuel consumption.

An Engine warning light shows the car computer has detected a host of engine malfunctions. This light can illuminate when an ECU detects underlying issues on any powertrain components and car sensors. That said, always find the cause of the light and fix it on time.

Most times, it’s tricky to trace a gas vapor leak unless it is large. Another sign a vehicle with a logged P0457 will project is an increase in gas consumption. This can be hard to identify, as there are many causes of lousy gas mileage. Aside from this, the increase in fuel consumption can be as slight as insignificant.

 What Are The Causes of Code P0457?

Identifying the cause of P0457 on Honda, P0457 on Dodge, or any vehicle can be a challenging task. The evaporative emission control system has several interrelated components. That said, issues can spring up from any of the components. These causes need to be systematically checked to track the root and fix them.

Here are the probable causes of a registered P0457 you should look into when diagnosing this error code;

  • Loose or defective gas cap
  • Stuck or damaged vent control valve
  • Faulty or stuck purge valves
  • Disconnected or cracked EVAP hoses
  • Cracked or lousy charcoal canister.

The uncommon cause of this diagnostic trouble code is a faulty sensor. A faulty EVAP switch or sensor could be all you need to fix and erase the code.

p0457 code

How Serious Is Code P0457?

Indeed, all evaporative emission control system fault codes are less severe. The P0457 error code is more severe than them all. It can decrease a vehicle’s fuel economy and cause the car to fail a smog inspection.

Depending on where the leak is coming from, it can escalate to a much larger leak with time. This could lead to an expensive repair and can even keep you stranded in the middle of nowhere.

Code P0457 Common Diagnosis Mistakes

Like I always emphasize, start from minor probable causes when diagnosing a fault on a vehicle. Many technicians and DIYers ignore this. They begin with the common causes and replace unnecessary parts, which equals superfluous repair bills.

Another common mistake is not following the complete troubleshooting procedures, causing you to overpay or underpay for a solution. For instance, fuel caps are cheap to replace, making people replace them without properly diagnosing the vehicle for the actual cost.

Tools Needed to Diagnose Code P0457

Diagnosing trouble code P0457 on Jeep Liberty or any vehicle requires some common tools. Here are the tools needed to troubleshoot the P0457 trouble code;

How to Diagnose Code P0457

Since P0457 doesn’t project any noticeable effects on a car other than an illuminated check engine light, you need an OBD-II scan tool to detect the cause of the light.

Once the OBD-II scan tool determines that the onboard diagnostic computer has registered P0457, do a visual inspection starting from the gas cap. If there’s a foreign material on the thread, cracks, or it’s worn out, replace it and erase the code. 

Clear the codes, test run the car and ensure the error code doesn’t come back again. If the code returns, the gas cap is not the culprit. Then, head on and inspect other EVAP system components.

How do you fix P0457?

The easiest fix for error code P0457 is to clean dirt on gas cap threads and tighten it properly or replace it. Other probable repairs include;

  • Repairing or replacing faulty evaporative emission control [EVAP] system’s vacuum hose.
  • Make sure there’s no leakage on the intake manifold fittings.
  • Replacing a cracked charcoal canister
  • Replace a clogged or leaking purge vent valve
  • Replace the wiring harness with the EVAP control purge valves.

Final word

This article has simplified the meaning of error code P0457 and outlined the symptoms and probable causes. Diagnosis and repair procedures will help you troubleshoot and fix the issue.

The fix could be a simple one. It’s essential to do thorough troubleshooting, as missing a common culprit as a loose gas cap can lead to replacing a costly component.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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