The Evaporative Emissions Control (EVAP) system is the system that is used to reduce the chance for fuel system emissions to evaporate and release unburned hydrocarbons into the atmosphere. During hot days, fumes in the fuel tank expand and when there is pressure build up, them is passed through the fuel vapor vent valve and the fuel vapor control valve to the EVAP canister where it is stored for some time until the engine can use it. The many elements of this system are installed underneath the vehicle; these are EVAP canister which is packed with activated charcoal, the check valve, dust separator and the canister vent solenoid. The fuel tank pressure sensor measures pressure inside the tank, and sends data to the PCM during leak tests. The fuel vapor vent valve regulates vapors that are to be admitted into the EVAP system while the fuel vapor control valve shuts off liquid fuel from entering the canister during fuelling. The canister vent solenoid is open most of the time and tests to seal the system and the EVAP check valve vents the air during refueling. The canister purge valve managed by the PCM controls the flow of the vapor into the intake manifold and its working is dependent on the manifold vacuum and the sensor. Some of the typical signs that indicate a defective-evaporative emission control system include foul smell of fuel, rough idle, and stalling, and in most cases, the hose connections and some of the components associated with the system are often checked for damages or leakage. To ensure that there is no increased fuel vapor pressure then the gas cap should be disconnected so that pressure can be heard to be escaping. Component replacement entails a step of disconnecting the battery and when replacing particular components, there is need to remove them and replace them with the right part and reconnection of the PCM for better performance.