A small leak in the purge valve or vent valve.A small leak in any of the EVAP hoses or fuel tank hoses.Evaporative (evap) emission system hose leaking.Evaporative (evap) emission canister or fuel tank leaks.Here are Some Possible Causes for an EVAP Code or an EVAP Leak: Everything will seem fine, except for the glowing check engine light on the dashboard. When your engine light comes on because of a weakness or failure in this system, you most likely won’t notice the car driving any differently. The EVAP system is a closed system that captures fuel tank vapors and prevents them from escaping into the atmosphere.

Here’s an example of a problem that can trigger the light… Trouble Code: P0456 Evaporative Emissions System – Small Leak Detected The purpose of the OBD system is to reduce tailpipe emissions, and your car is programmed to alert you any time the engine control computer detects that a sensor or system isn’t performing the way it’s supposed to. The light is part of your vehicle’s on-board diagnostics (OBD) system and can indicate anything from a quick fix like a loose gas cap to a major repair like a failing catalytic converter. Your car’s “Check Engine” or “Service Engine Soon” light can flash on for more than 1,400 different reasons.

2001 jeep grand cherokee/gas tank leak