Common Causes of Car Evap System Failure

If you’ve owned your car long enough, you may have experienced something that all car owners dread: the dreaded check engine light coming on while driving. While all sorts of issues can cause this light, one of the most common and frustrating ones is what’s known as an evap system failure. Here are some of the most common causes of evap system failure so that you know what’s wrong with your vehicle before it becomes a bigger problem than it needs to be.

What is an Evap System

The Evaporative Emission Control System, or evap system, is part of your vehicle’s fuel delivery system. The evap system is responsible for preventing vapor leaks from the fuel system. Without a properly functioning evap system, fuel would evaporate even if the engine isn’t running. So instead, vapors from the fuel tank are directed into a charcoal-lined canister that stores the vapors until enough is present. They are then released into the engine’s combustion chamber to be burned as fuel. If the evap system fails, you will notice several signs you should not ignore.

Signs of a Failing Evap System

There are several common issues caused by evap system failure, including a loud hissing sound from the fuel tank, the smell of fuel coming from the vehicle due to the escape of vapors into the air, excessive smoke from the car’s exhaust, and problems pumping gas and filling the tank. In addition, failure of the evap system will typically cause the Engine Control Unit (ECU) to give an error message resulting in an active check engine light. While many problems can cause the check engine light to illuminate in conjunction with any of these other signs, it’s a safe bet your evap system is failing.

How is an Evap System Repaired

Suppose you notice any symptoms of a failing evap system; it’s crucial to have them diagnosed by an auto care technician. Evap canister or evaporator replacement is a relatively simple job that an experienced mechanic can perform without much trouble. However, it is essential to consult a professional to get this repair done because leaking fuel vapors can be dangerous and ignited by metal-on-metal contact. Fortunately, evap system repairs are usually not very costly if caught before engine damage occurs.

If you notice any of the signs of a failing evap system, don’t ignore them. Instead, see your trusted mechanic have your car’s issues diagnosed and repaired before the problem gets worse.

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