Evaporative Emission Control System
Auto Engines,  Cars

How To Save My Car From Evaporative Emission Control System (EECS) Leak?

Whenever we think of automotive emission, we usually think some dirty stuff is coming out of the exhaust pipe. The internal combustion creates CO2 and nitrogen oxide released into the air when we drive. But no one knows there are so many other types of emission that can come out of our car.

They are evaporative emissions, and the gasoline in your fuel tank will slowly evaporate over time. These emissions contribute to air pollution and other health issues to humans. There are things you can prevent your car from evaporative emission control system leak. First, let us see what evaporative emission control system is.


What is an Evaporative Emission Control System?

Evaporative Emission Control System leakage

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The evaporative emission control system is powerful enough to capture raw fuel evaporating from the fuel storage system. The system doesn’t require any maintenance, but faults can turn the check engine light, preventing the vehicle from passing an emission test.

A car has a closed EVAP system, and it immediately captures the fuel tank vapors preventing them from escaping to the atmosphere.


What is EECS Leak?

An evaporation leak in a car is due to the fault in the emission control system, and it functions taking gas fumes from the tank reaching to the atmosphere. When the engine computer recognizes large leak in the control system, the vehicle’s EVAP system will be sealed.

The main purpose is to prevent the gasoline vapors escaping into the atmosphere. The leak in the car is caused due to the fault in the emission control system.

It prevents the smell of fuel reaching inside your vehicle. The fuels we use in our cars consist of more than 150 chemicals, and if we inhale these ingredients, it may cause breathing problem, dizziness, and headache. The evaporated gasoline also causes smog. For these reasons, car makers should install the system in their vehicle to mitigate the gasoline evaporation.

Evaporative Emission Control System leakage

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Symptoms of Leak

  • One main symptom of the leak is the check engine light blinking when you are driving. You may also notice a slight fuel odor. Then, you must immediately check the gas cap.
  • Some cars may show a slight drop in gas mileage.

Causes of Leak

  • The common cause of the leak remains the gas cap not closed. If the cap is not closed, the check engine light will blink.
  • Damaged gas cap seal.
  • There can be a leak in the hose system.
  • Other issues can be a defective purge valve, defective leak detection pump, and a faulty vent o-ring seal.
  • Leak in charcoal canister and fuel tank leak.

Is It Safe to Drive with the Leak?

Even it is safe to drive your car with EVAP leak; you shouldn’t drive your vehicle for long. Once you notice the engine light blinking, make sure the gas cap on your car is fastened. If the light is still on, you need professional help to repair the leak.


How the Mechanics Diagnose the Leak?

  • The mechanic will hook up a scan tool to the vehicle’s DLC port and will check for a P0442 code.
  • He will then examine the data associated with the code which will show the circumstances present in the vehicle at the time of a malfunction.
  • He will check for the crack in the fuel tank and charcoal canister.
  • He will inspect the condition and fit of the gas cap and will test the gas cap tester.
  • He will perform a smoke test on the EVAP system in search of smoke that indicates a vapor leak.
  • He will use a scan tool to monitor the tank pressure and to confirm the leak.
  • Then he clears the code and test drive the vehicle.

How to Save your Car from EECS Leak?

The EVAP system is premeditated to trap the fumes of a gas tank. The system contains liquid-vapor separator, fuel tank, and vapor lines to prevent gas from entering the system. EVAP canister has purged valve inside the canister to trap the fumes.

Sometimes, when the car engine operates, the purge valve gets opened up, allowing fresh air to get inside the canister. This force the gas fumes get back inside the engine’s air intake, and then it starts burning inside the engine.

When the system develops a leak due to corrosion, the system starts showing an EVAP leak code on the system. To resolve the problem, you have to find out the leak component and replace it. Some repair needed to fix the problem includes:

Evaporative Emission Control System leakage

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  • Replace the fuel tank and the gas cap
  • Replace the charcoal canister and EVAP system lines
  • Replace the vent valves

Qualified technicians are required to diagnose the problem. Commonly the gas cap would be the issue, and if the gas cap is overlooked, you can save time and energy by diagnosing other components. Professional level tools are required to diagnose such leaks in an accurate way.

An advanced live tool can provide access to live data and control on EVAP system. They are helpful in dealing with such leaks. Most leaks are much smaller than eyes can see, so a smoke test has to be performed to find the fuel vapor leaks. A specialized smoke machine will pressurize the fuel system and will add smoke to find the smallest leak.

Gasoline is volatile, and it evaporates quickly. Your car’s fuel can turn from liquid to gas very fast when it is hot outside. This hydrocarbon emission from cars coming through fuel evaporation is not good for the environment. So, you must take preventive measure of leaking the gas from your car. Some things can be done to prevent your vehicle from evaporating gasoline.

  • First, you must make sure the fuel cap is secured tightly. If you don’t have a fuel cap, get one immediately. Fuel can escape from the tank if it is not airtight.
  • Whenever possible, you must park your vehicle in the shade during the summer season. Even though latest cars are equipped with an advanced EVAP system to prevent evaporation from happening, gas will still evaporate from the tank if your vehicle is parked in the sun. Parking in the shade will keep your vehicle cooler and reduce fuel from evaporation.
  • You must try to fill fuel in your vehicle during the early morning or late night. It remains warmer during the afternoon and early evening. This would prevent gas from getting evaporated.
  • To keep the EVAP system operating properly, you must re-install your vehicle’s gas cap immediately after refueling. Addition to that, you must apply for a good rust protection to keep the system line corrosion to a minimum. Make sure you always check the engine lights. If the lights are not kept off, the EVAP system can create problems leading to a major repair cost.

Fuel vapors can emit from your vehicle anytime whenever there is gasoline in the tank. So, if there is a leak even if you are driving the vehicle, the vapors will pollute air within 24 hours. Whenever the engine light blinks, you must expect a leak in your EVAP system. If you face any such situation, it is best to contact a mechanic immediately to have a look of your vehicle.