Q: What is the purpose of the Evaporative Emissions Control (EVAP) system and Vapor Canister?
A: The Evaporative Emissions Control (EVAP) system prevents fuel vapors from escaping into the atmosphere. On warm days, these vapors expand and are routed to the EVAP canister for temporary storage. The Powertrain Control Module (PCM) then allows these vapors to be drawn into the engine. The EVAP canister, located under the vehicle, contains activated charcoal and requires no maintenance. Other key components include the fuel tank pressure sensor, fuel vapor vent valve, and canister vent solenoid. Symptoms of a faulty EVAP system include a strong fuel smell and poor driveability. Diagnosis and repair should be done with an OBD-11 scan tool and by a qualified repair shop. Component replacement involves detaching vacuum lines and replacing the canister.