Posts Tagged: loose gas cap cause a check engine light

Why does a loose gas cap cause a check engine light?

How does a loose gas cap cause a check engine light? Vehicles are equipped with an evaporative emissions system that captures fuel vapors as you fill your tank. Venting fuel vapors into the air causes air pollution and smog. So modern vehicle have a sealing gas cap to prevent fuel vapors from escaping. This article explains how a loose gas cap can cause a check engine light. How does the evaporative emissions system work? As you fill your tank with fuel, vapor pressure builds up in the tank, pushing the … Read More