Q: What is the function and components of a vehicle's Evaporative Emission Control (EVAP) system,Purge Valve,Fuel Pressure Sensor and Vapor Canister for Cadillac DeVille and DTS?
A: The EVAP system in a car is desigend to trap and hold fuel vapor from the fuel tank and intake manifold. It comprises a canister filled with charcoal and several lines that connect it to the throttle body, the fuel tank, and the atmosphere. Typically, this canister is positioned under the vehicle near the fuel filter. Fuel vapors are collected when an engine is off from different parts such as intake manifold, throttle body and fuel tank they are stored at the canister. In case of operation of the engine these fuels are pushed out of canister into combustion by an airflow during purge process via charcoal. The purge valve solenoid which is used to open or close a mechanically actuated valve called a purge valve, was present on some older models; its place among other components has been standardized on today's vehicles. Rarely does EVAP system fail but old vehicles may have leaks causing loss of fuel vapour hence leading to environmental concerns alongside wastage of oil products. Obvious signs of malfunctions include smells of gasoline along with bad idle wether stalling or reduced drivability that could be accounted for by problems related to purging valves gone wrong, broken tanks, cracked hoses or wrong hose connections. There may be difficulties with finding leaks because there is so much tubing and ducting in this system but look underneath the vehicle might reveal obvious problems like leaking tubes therefore if you cannot find where they coming from then it would be better for you to get a professional pressure test done on your system. If diagnosed diagnosis , components in question including EVAP canister purge valve, EVAP vent valve, evaporation (EVAP) canister or fuel tank pressure sensor etc., most times that replacement can usually be carried out by following relevant procedures for removing & installing them at home though sometimes requires experts in repair works only.