Understanding Your Vehicle’s EVAP System
As you drive, your vehicle’s oil and fuel produce vapors that are very harmful to the environment. Because of this, Evaporative Emissions Control Systems (EVAPs for short) are mandated in all cars, trucks, and SUVs.
The EVAP system works by drawing in fresh air, gathering the unburned vapors, and delivering them to the intake system, where they can be re-burned in the engine—essentially recycling them. If there’s a problem with the EVAP system, such as a leak or blockage, a trouble code will be generated, and the check engine light will come on.
What Causes Issues with the EVAP System?
The EVAP system is a complicated network of hoses, valves, filters, and other components. While any of these parts can cause an issue with the system that triggers the check engine light, some of the most common problems include:
- Faulty or loose gas cap
- Damaged gap cap O ring
- Damage gas tank filler tube
- Vacuum feed line leaks
- Vacuum control valve leaks
- Damaged vapor tube
- Leaking charcoal canister
Although it’s not dangerous to drive with an EVAP leak, it’s best to get the issue repaired as soon as possible. Not only is it harmful to the environment, but it also impacts performance and drivability. You may notice:
- The check engine light is on
- Poor fuel economy
- The fuel system service light is on
- Engine surging or stalling while driving
- Engine hesitation or misfires
- Low power or a lack of power
- The smell of burning carpet or fuel in the cabin
- Excessive smoke coming from the exhaust pipe
The EVAP System and the Check Engine Light
Issues with the EVAP system are one of the top 5 reasons for the check engine light to come on. While EVAP problems don’t generally lead to vehicle damage, the fact that they trigger the check engine light means that other issues can be masked if you wait too long to get a repair.
There are hundreds of issues that can cause the check engine light to turn on—but there’s only one light to signal them. So if the light came on because of an EVAP issue that hasn’t been fixed, and another problem arises, you won’t be alerted to the new issue because the light is already on.
Getting Your EVAP System Repaired
At your repair appointment, one of our technicians will pull the trouble code and begin performing diagnostics to determine the cause of the issue. In some cases, we may test the valves to find a blockage or perform a low-pressure smoke test to find the leak. After performing the necessary repairs, we’ll reset your check engine light.
EuroCar Service specializes in all European vehicles, including Audi, BMW, Land Rover, Mercedes, Mini Cooper, Saab, Volkswagen, Volvo, Smart Car, Fiat, and Jaguar. Call us today at 206-527-8828 or request an appointment online.