The EVAP system monitor checks for fuel vapor leaks by performing either a pressure or vacuum test on the fuel system. For 1996 through 1999 vehicles, the federal standard allows leaks up to the equivalent of a hole .040 inches in diameter in a fuel vapor hose or filler cap. For 2000 and newer vehicles, the leakage rate has been reduced to the equivalent of a .020 in. diameter hole, which is almost invisible to the naked eye but can be detected by the OBD II system. Finding these kinds of leaks can be very challenging. According to one expert, you can find a .040 in. leak with an ultrasonic leak detector but not a .020 in. leak. For such a small leak, you need a smoke or dye-type detector.
Evaporative System Integrity Monitor (ESIM). It regulates the presure and Vacuum in your fuel/evap system.
evaporative emission control system incorrect puge flow
Evaporative Emission System Switching Valve Control Circuit/Open This is referring to a problem with the evaporative emission system. A technician should be able to determine exactly what part of the system is malfunctioning.
The primary function of the evaporative emissions system (EVAP system) is to regulate the engine and fuel tank vapors. It keeps the vapors from being released into the air by collecting them in an activated charcoal storage tank.
Monitor your brains
P0440 sets when the evaporative emission system large/medium leak monitor test fails. Normally meaning there is a leak in the system. This can happen from a loose or not sealing gas cap, solinoid valve not working or not sealing, or a brocken/cracked emission hose. Best bet is to do a visual inspection of the evaporative emission system and replace anything that is broken or unhooked. If you can find anything take it to a repair shop and have a evap system leak test performed. Most new OBDII car can be forced to run the monitor test with a handheld scan tool with the correct software installed.
Large vapor leak in the evaporative emmisions system
P0441 Evap Purge Flow Monitor Insufficient or excessive vapor flow detected during evaporative emission system operation
Trouble code P0455 means:EVAP Large Leak DetectedLarge vapor leak in the evaporative emmisions systemTrouble code P0455 means: Evaporative Emission System Leak Detected (gross leak/no flow)Large vapor leak in the evaporative emmisions system
P0456 Evap Leak Monitor Small Leak Detected Leak has been detected in the evaporative system You have a .020 inch leak in the fuel vapor system. Could be anywhere form the gas cap to the engine.
Evaporative cooling
Evaporative Emission Control System Malfunction