You’ve probably never considered what happens when the charcoal canister in your car goes bad. That’s because it’s possibly one of the most reliable parts of your vehicle.

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The charcoal canister (aka: EVAP canister) is an essential part of the Evaporative Emission Control System (often shortened to “EVAP”). This system helps ensure that dangerous fumes from your gas tank aren’t released into the environment and instead puts them to work powering the engine.

There are times when this part is damaged or becomes faulty after years of use. Because charcoal canisters rarely degrade, it’s helpful to be familiar with the symptoms, so you know what to do next, and how much this repair will set you back.

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Bad Charcoal Canister Symptoms

How a Charcoal Canister Works

To put it simply, the charcoal canister in your car absorbs excess gasoline fumes and vapors that accumulate in your gas tank.

The charcoal in this part is activated carbon, which is manufactured to be very porous. These pores help maximize the amount of gas and toxins that the canister can absorb.

Here’s a video showing the inside of a typical charcoal canister:

Periodically, the charcoal canister empties by pushing this excess vapor into the engine through the fuel vapor vent line and purge valve.

Without the charcoal canister, these vapors would either collect in the gas tank or be vented from the car into the atmosphere. These vapors are often toxic and dangerous for the environment.

Because the canister collects this vapor and then uses it to power the engine, the EVAP system helps cars be safer for the environment and more efficient.

The relatively simple construction of the charcoal canister means that it’s generally self-sustaining. However, there are some situations where it gets damaged or wears out. One of the most common charcoal canister problems is caused by “topping off” your gas tank, which can cause an overflow of fuel to flood the canister.

Bad Charcoal Canister Symptoms

#1 – Check Engine Light


The total cost for a charcoal canister replacement can range from $150-$630. Depending on your vehicle’s make and model, a new part usually costs between $100 and $500. If you hire a mechanic for the replacement, you can expect to pay an additional $50 to $130 in labor.

Charcoal canisters are generally easy to access. However, working on the EVAP system can be a bit tricky, so make sure to check your car’s manual for more information on how to do this repair.

Is it Safe to Drive With a Faulty EVAP Canister?

In most circumstances, it is safe to drive with a bad charcoal canister. The biggest concern most owners will face regarding a damaged EVAP system will be that your vehicle will release more fumes into the environment.

If you’re a driver that is concerned about your carbon footprint, this may motivate you to fix your charcoal canister as soon as possible. But even if you sit on the other side of the climate change debate, replacing the canister should be a put on your to-do list.

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However, if your defective charcoal canister causes a strong fuel smell inside your vehicle, you’ll want to expedite this repair. As already mentioned, being exposed to fuel vapors can be extremely dangerous. If you must drive, roll down a couple windows to let fresh air into the vehicle.