---
title: "What Is an EVAP Leak And How Do You Diagnose It?"
description: "If your car is showing any of these symptoms of an EVAP leak, you should get it repaired quickly. Here's everything you need to know including the cost."
date: "2021-01-11"
modified: "2021-01-11"
authors:
  - name: "Chris Teague"
    job_title: "Contributor"
    link: "https://www.thedrive.com/authors/chris-teague"
url: "https://www.thedrive.com/maintenance-repair/38194/evap-leak"
categories:
  - "Maintenance & Repair"
  - "The Garage"
tags:
  - "commerce"
  - "NoAds"
---

# What Is an EVAP Leak And How Do You Diagnose It?

![](<https://www.thedrive.com/wp-content/uploads/images-by-url-td/content/2020/12/Depositphotos_2742744_xl-2015-e1609189030615.jpg>)
*\<em\>www.thedrive.com</em>*

Check engine lights are sometimes accompanied by noises, smells, and vibrations that can help diagnose the underlying issue. But sometimes, that annoying little light comes on with no other indication of what’s up. That’s sometimes the case with leaks in the EVAP system.

What is an EVAP leak, you might be asking? We’ll get to that. Right now, the important things to know up front is that the EVAP system is related to your vehicle’s emissions control systems and that it’s responsible for protecting the environment from the nasty stuff that the vehicle produces. That’s good!

If there’s a leak, your car won’t burst into flames, but it’s not a problem you should ignore. That’s not! In this post, *The Drive’s* screw-loose editors will tell you why that is, and will also get into what causes the leaks and how you can [diagnose them yourself](<https://www.thedrive.com/reviews/27479/best-obd2-scanner>). Onward!

![A mechanic can help diagnose the issue.](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1609187467518-depositphotos_89009022_xl-2015.jpg>)
*A mechanic can help diagnose the issue., *Depositphotos**

## What Is The EVAP System?

Your vehicle’s EVAP system (evaporative emissions control systems) are in place to prevent fuel tank vapors from escaping into the atmosphere. All cars and trucks are required to have an EVAP system to protect the environment from harmful fuel vapors and you from breathing them in.

## How Can I Tell If There’s A Leak?

The main indicator that accompanies EVAP leaks is the check engine light. You may notice a faint fuel odor, but the problem manifests itself differently in different vehicles. A common issue is a loose gas cap, which can cause the check engine light to come on in newer vehicles as the ECU senses a problem with the EVAP system. If you see the check engine light and haven’t filled up with fuel recently, it’s a good idea to [use a code reader](<https://www.amazon.com/Autel-AutoLink-AL319-Scanner-Automotive/dp/B007XE8C74?tag=drive09e6-20>) or [take your vehicle to a shop](<https://www.anrdoezrs.net/links/9260165/type/dlg/sid/td-exhaust-leakts-info/https://www.goodyear.com/en-US/services/auto-services>) for diagnosis.

## Is It Safe To Drive With An EVAP Leak?

It’s technically safe to drive with a leak, but it’s absolutely not recommended. You *probably* won’t burst into a ball of flames while driving, but you will be exposing other people and the planet to your vehicle’s fumes. That’s not a good look.

## How Much Will This Cost To Fix?

Depending on where the leak is in the system and whether or not there is another damage, you can expect to pay up to $600 or so to fix a leak in your vehicle’s EVAP system. If you have an OBD2 code reader at home, you can diagnose the problem yourself, but it’s best to leave the fixing to the professionals.

## EVAP System Terms You Should Know

Get educated!

### EVAP System

As part of a vehicle’s emissions control system, the EVAP (evaporative emissions control) system traps fuel vapors from evaporated fuel. The system then sends the fuel back to the tank for use.

### Emissions

Emissions refer to the gases, vapors, and other pollutants that are emitted from the daily use of vehicles.

### Check Engine Light

The check engine light is a warning indicator that is illuminated when the vehicle’s electronic control unit (ECU) detects a problem with a system, sensor, or component. It’s frequently seen in combination with noises, vibrations, and other symptoms, but with an EVAP leak, it might be the only indicator that something is wrong.

### OBD2

OBD2 or on-board diagnostics systems are a vehicle’s self-diagnostic and reporting mechanisms. The vehicle’s computer generates codes that correspond to various issues, which can be read and interpreted with a scanning tool at home or at a repair shop.

![message-editor%2F1609187517895-depositphotos\_33465699\_xl-2015.jpg](<https://www.thedrive.com/wp-content/uploads/content-b/message-editor/1609187517895-depositphotos_33465699_xl-2015.jpg>)
*Tailpipes are just one source of pollution., *Depositphotos**

## Get Mobile Evap System Service and Repair with YourMechanic

While The Drive’s how-to guides are detailed and easy to follow, no vehicle is created the same, and not all auto maintenance or repair tasks are easy to accomplish on your own. That’s why we’ve partnered with [YourMechanic](<https://www.yourmechanic.com/book/summary?utm_source=thedrive&utm_medium=web&utm_campaign=thedrive>) and their network of mobile automotive technicians to offer our readers $10 off a $70 or more service call when you use promo code **THEDRIVE**.

## FAQs About EVAP Leak

You’ve got questions, *The Drive* has answers!

## Let’s Talk, Comment Below To Talk With The Drive’s Editors!

We’re here to be expert guides in everything How-To related. Use us, compliment us, yell at us. Comment below and let’s talk! You can also shout at us on Twitter or Instagram, here are our profiles.

Jonathon Klein: Twitter ([@jonathon.klein](<https://twitter.com/jonathon_klein>)), Instagram ([@jonathon\_klein](<https://www.instagram.com/jonathon_klein/>))

Tony Markovich: Twitter ([@T\_Marko](<https://twitter.com/T_Marko>)), Instagram ([@t\_marko](<https://www.instagram.com/t_marko/>))

Chris Teague: Twitter ([@TeagueDrives](<https://twitter.com/TeagueDrives>)), Instagram ([@TeagueDrives](<https://www.instagram.com/teaguedrives/>))

https://youtube.com/embed/nEhci3tpcGA

## Featured Products

We know you have plenty of options when it comes to products to help you with an EVAP leak. That’s why we’ve avoided jabbing you with a hard sales pitch. Instead, we’ve chosen a [handful of our favorite products](<https://www.thedrive.com/maintenance-repair/35067/how-to-recharge-car-ac>) that have received great reviews, are reasonably priced, and that are high quality.

[Innova CarScan Pro OBD2 Code Reader](<https://www.amazon.com/INNOVA-CarScan-5210-Code-Scanner/dp/B07Z46L5FG/?tag=drive09e6-20>)

[Car Fuel Leak Detector](<https://www.amazon.com/Detectors-Diagnostic-Automotive-Motorcycles-Snowmobiles/dp/B08J3YZZ3Q/?tag=drive09e6-20>)

[Pro-Lift Jack Stand](<https://www.amazon.com/Pro-LifT-T-6906D-Double-Jack-Stands/dp/B074R17GL4/?tag=drive09e6-20>)

*Got a question? Got a pro tip? Send us a note:* [*guidesandgear@thedrive.com*](<mailto:guidesandgear@thedrive.com>)

## Author
After working in the technology and software industry for several years, Chris Teague began writing as a way to help people outside of that world understand the sometimes very technical work that goes on behind the scenes. With a lifelong love of all things automotive, he turned his attention to writing new vehicle reviews, detailing industry trends, and breaking news. Along the way, he earned an MBA with a focus on data analysis that has helped him gain a strong understanding of why the auto industry’s biggest companies make the decisions they do.

### Author social links  
[Instagram](<https://instagram.com/TeagueDrives>)  
[Twitter](<https://twitter.com/TeagueDrives>)