EVAP Canister Functions, Symptoms, and Repair Cost

The EVAP (Evaporative Emission Control) system is one of the many emission systems found in modern vehicles. This system helps to prevent fuel vapors from being released into the environment by trapping them within the vehicle.

An important part of this EVAP system is the EVAP canister. It is essential to recognize if your EVAP canister has any malfunctions as soon as possible since it is an integral part of the EVAP system. Taking prompt action in regard to a faulty EVAP canister will help you avoid additional complications and expensive repair costs in the future.

This article will help you know how the EVAP canister works, the signs of a faulty EVAP canister, and what to do when your EVAP canister is faulty.

How Does the Evap System Work?

The car’s Evaporative Emission Control (EVAP) system is responsible for preventing the release of harmful gasoline vapors into the atmosphere. When a vehicle is operating, heat and movement inside the fuel tank cause these vapors to be produced.

These are then transmitted through a vent line to a charcoal canister that contains activated carbon pellets. The pellets absorb and store the gas vapor until they are released when an engine runs.

When the engine is active, the purge valve opens and allows the engine vacuum to pull gasoline vapors from the charcoal canister into the intake manifold. Subsequently, these gases get combusted with air-fuel mix inside of the combustion chamber.

If the onboard computer of a vehicle recognizes any leakage or malfunctions in its EVAP system, it will activate the “Check Engine” light and store a diagnostic trouble code in its memory.

Also Read: 6 Bad Transmission Shift Linkage Symptoms (And How to Fix)

Symptoms Of Bad EVAP Canisters

EVAP Canister

1. Hissing Sound

Sometimes, after driving for a long period of time, the EVAP canister might not be able to balance the air pressure on time. This will cause a hissing sound in the fuel tank, which you will hear when you want to refuel your vehicle.

If the hissing sound is much louder than normal, and you feel the air rushing through, your EVAP system is faulty and isn’t purging enough fuel vapor.

2. Smell of Gasoline

A strong smell of gasoline, especially near the fuel tank, can be a sign of a failing EVAP canister. This is because the gasoline vapors are not being captured and recycled properly, resulting in a leak.

3. Check Engine Light

A failing EVAP canister can trigger the check engine light to turn on, signaling a problem with the emissions control system.

4. Failed Emissions Test

A malfunctioning EVAP canister can cause the vehicle to fail an emissions test. This is because the canister is not able to capture and recycle the gasoline vapors, resulting in higher emissions.

5. Poor Gas Mileage

A failing EVAP canister can also result in decreased fuel economy. This is because the canister is not able to capture and recycle the gasoline vapors, resulting in more fuel being used.

6. Poor Engine Performance

When your gas canister gets damaged, it will cause poor performance in your car’s engine. Thereby reducing its efficiency and making your car or truck move sluggishly, irrespective of the pressure you apply on your gas pedals.

If the EVAP canister is broken, the fuel won’t burn completely. This needs to be fixed right away because your car won’t move as quickly. If left unattended, it can get worse.

7. Rough Idling

A malfunctioning EVAP canister can cause the engine to run rough at idle or during acceleration. This is because the canister is not able to properly capture and release the gasoline vapors, causing a disruption in the air/fuel mixture.

How to Replace EVAP Canister

Replacing the EVAP (Evaporative Emission Control) canister requires some mechanical knowledge and experience. Here are the general steps involved in replacing the EVAP canister:

  1. Locate the EVAP canister: The EVAP canister is typically located near the fuel tank or in the engine compartment. Refer to the vehicle’s owner manual or service manual for its exact location.
  2. Disconnect the electrical connector and hoses: Once you have located the EVAP canister, disconnect the electrical connector and hoses that are connected to it.
  3. Remove the mounting bolts: Use a wrench or socket set to remove the mounting bolts that are holding the canister in place. Be careful not to damage any other components or electrical connections in the process.
  4. Install the new EVAP canister: Install the new EVAP canister in place of the old one, and secure it with the mounting bolts.
  5. Reconnect the electrical connector and hoses: Reconnect the electrical connector and hoses that were disconnected earlier. Make sure they are properly seated and secured in place.
  6. Test the new EVAP canister: Start the vehicle and check for any signs of gasoline smell or rough running. It is also a good idea to have the vehicle inspected for emissions to ensure that the new canister is working properly.

It is recommended to have a qualified mechanic perform the replacement if you are not familiar with the process. Additionally, some vehicles may require additional steps, so refer to the service manual for your specific make and model.

EVAP Canister Replacement Cost

Replacing an EVAP canister yourself is not too difficult, but it requires careful consideration and referencing of your car manual. If you choose to do the work yourself, you will need to purchase new parts, which may cost between $100-500. Alternatively, if you decide to call a mechanic for help replacing the part, be prepared to spend anywhere from $150-630 total. This includes both the expense of new parts, which cost between $100-500 and labor costs ranging from $50-$130.

How Much Will It Cost to Repair An EVAP Leak?

There are two major factors that determine how much you’ll spend on repairing an EVAP leak. They are: the cause of the leak and where the leakage occurs.

Replacing a canister should cost you around $100-600. Another factor that can determine the cost is if the repairs you are making require you to replace the important parts of the EVAP system, in which case you would have to spend more money on repairs and labor. The causes that are minor won’t cost you much to get fixed.

Another factor that will also determine the cost of repair is the type of vehicle model you drive. Depending on your vehicle’s model, the cost of automobile parts is different. While some car models require parts that are affordable, other car models require automobile parts that are very expensive.

You might want to fix the place in your EVAP system that has a leak in order to save money on buying new ones, but it is wiser to get them replaced. This is because fixing the damaged areas won’t last you very long. Instead of fixing it regularly and spending (not to mention the cost of labor), it is better to have a replacement that will last you a long time.

Ignoring or finding alternatives for the faulty components of your EVAP system is dangerous, as this can cause more harm to your vehicle, especially when the alternative measures you take aren’t correctly done.

Also Read: Power Steering Assist Fault (Meaning, Causes & Fixes)

Frequently Asked Questions

Can an EVAP Canister Be Cleaned?

Yes, EVAP canisters can be cleaned with pressurized air or a vacuum. However, it is always best to consult the specific user manual for your vehicle to ensure that the cleaning procedure you are using is appropriate and won’t cause any further damage.

Will My Car Run Bad Without an EVAP Canister?

Your vehicle’s engine will not perform poorly because of a faulty vapor canister, even if the canister itself is defective. However, this can result in your vehicle failing an emissions test as well as releasing pollutants into the surrounding environment, depending on the severity of the situation.

You might think that removing your EVAP canister from your car permanently and than replacing it when it breaks is a good idea, but you should give this some serious consideration because tampering with emission equipment is against the law, and you should therefore avoid taking the risk.

Is it Safe to Drive With a Faulty EVAP Canister?

No, it is not safe to drive with a faulty EVAP canister. The EVAP (Evaporative Emission Control) system is part of the vehicle’s emissions control system that helps reduce potentially harmful vapors from escaping into the atmosphere. A fault in this system can cause a loss of engine power and fuel economy, and may also lead to more serious issues such as damage to other components or instability at higher speeds.

What happens if you don’t replace your EVAP canister?

If an EVAP canister is not replaced, fuel vapors may build up in the system unchecked, resulting in poor vehicle performance or potential damage to surrounding components. Additionally, emissions will increase significantly as those vapors are released into the atmosphere without passing through their required filtration process. In many states, failing an emissions test due to a faulty or empty EVAP canister could result in fines and other legal penalties.

How do I know if my EVAP canister is clogged?

There are a few different ways that you can tell if your EVAP canister is clogged. If there is an abnormal smell or combustible odor coming from the area of the vehicle where the canister resides, this could be a sign that it’s clogged. Another symptom would be having either hard starts or rough idles when starting up your vehicle and this could also indicate a blocked evaporative emissions system (EVAP). Lastly, increased fuel consumption while driving may also point to an issue in the EVAP system.

Is an EVAP leak serious?

Yes, an EVAP leak can be a serious problem since it potentially releases harmful vapors into the atmosphere. This can cause environmental damage, and may also lead to engine performance issues due to the loss of fuel vapor in the system. To prevent further problems from arising, an EVAP leak should be addressed as soon as possible.

How long does it take to replace EVAP?

The amount of time it takes to replace an EVAP system can vary widely depending on the size and complexity of the vehicle’s EVAP system. Generally speaking, replacing an EVAP system in a passenger car can take between three and six hours. Replacing one in a larger vehicle with more complex systems could take up to eight hours or longer.

Final Thoughts

It is very important to have a solid understanding of what an EVAP canister is and what to do in the event that your EVAP canister develops a fault.

This is due to the fact that the EVAP canister is a very important component of the EVAP system in your car, which ensures that your vehicle continues to function properly. In this article, each of these topics has been discussed in detail.

Leave a Comment