Back to Blog
Evap system monitor5/30/2023 ![]() It is not intended to be exhaustive, complete, or even applicable to all situations. The information presented below is an example of diagnostic strategies that a technician might employ while diagnosing your vehicle’s EVAP system. Loose and missing gas caps are not the only cause of EVAP system leaks, but they are the number one suspect. Under specific conditions, often while your vehicle is parked overnight, your vehicle’s on board diagnostic system (OBDII) will perform a series of EVAP system tests.ĭuring EVAP testing, a loose or missing gas cap will be detected as a leak, a diagnostic trouble code will be stored, and the MIL will illuminate.Ī loose gas cap might result in a P0442 code, (Small leak detected), and a missing cap could return a P0455 (Large leak detected). When many people see a “Check Engine Light” (Proper name: Malfunction Indicator Light a.k.a MIL) they immediately think, “Check the gas cap”. That’s because a missing, loose, or damaged gas cap often is the cause of an illuminated MIL due to a failed EVAP leak test. These fuel vapors are added to the engine’s air fuel mixture and are burned off as part of the normal combustion process. When your engine is running and warmed up, engine vacuum siphons stored fuel vapors from the EVAP canister and into the intake manifold. How Does The EVAP System Work?Īs stored fuel in you r gas tank evaporates fuel vapors are collected and stored in a canister filled with activated charcoal ( the EVAP canister). That’s why hydrocarbon control and reduction is a major component of your car’s emissions control strategy. These compounds are also known to cause eye irritations and respiratory problems. Photo chemical smog is that brown hazy stuff that nobody wants to see in the sky. Why?įuel vapors are composed of hydrocarbon molecules (HC) which when exposed to sunlight and oxides of nitrogen (NOx) result in photo-chemical smog. The evaporative emissions control system (EVAP) on your vehicle is designed to prevent fuel vapors from escaping into the atmosphere from your gasoline tank. Evaporative Emissions Control System (EVAP) What Does The EVAP System Do?
0 Comments
Read More
Leave a Reply. |