How to Solve Evaporative Emission System Leakage?
2 Answers
Evaporative emission system leakage treatment method: First, remove the vacuum hose on the activated charcoal canister, then check if the solenoid valve is faulty. If the solenoid valve is faulty, replace it. The following are the impacts of evaporative emission system leakage: 1. Difficulty in engine starting, no idle or unstable idle, black smoke from the exhaust pipe: When the filter at the air inlet at the lower end of the activated charcoal canister is clogged with dust and impurities, the fuel vapor adsorbed by the activated charcoal can reach a saturated state and become liquid fuel, entering the cylinder through the air hole above the throttle valve, resulting in an overly rich mixture. 2. Exceeding tailpipe emission standards, increased fuel consumption: Under normal EVAP operation, if the air inlet at the lower end of the activated charcoal canister is blocked, preventing the engine intake system from normally inhaling fresh air, and the fuel vapor adsorbed in the activated charcoal canister cannot be timely removed, air can only enter through the intake valve of the fuel tank cap, causing the fuel tank to often operate under negative pressure during fuel supply, thereby increasing the evaporation rate of fuel in the tank.
I previously encountered an evaporative emission leak issue while repairing my car. Usually, the first thing to check is whether the fuel tank cap is tightened properly—it's such a common problem. A loose cap can allow vapor to escape, and a simple test can resolve it. If the warning light remains on, I then inspect the hose connections throughout the system, especially those running from the fuel tank to the engine compartment, as aging and cracks often occur here. Using an OBD scanner to read the fault codes helps pinpoint the leak location, such as a damaged charcoal canister or valve that needs replacement. The entire system is designed to prevent gasoline fumes from escaping into the air. A leak not only pollutes the environment but also keeps the engine light annoyingly lit, wasting fuel and affecting performance. Small issues like replacing hoses are simple enough to handle myself, but for more complex situations, visiting a professional shop is a hassle-free choice. Regular maintenance and inspections of these components can help avoid unexpected expenses and troubles.
