How many components make up the EVAP system and what are they?,....I obviously have some kind of leak-to-the-atmosphere 'hole' in the system someplace.My wife'* '01 SE had some trouble getting her car to pass the Upstate NY(there'* a big differnce in the downstate/NYC test)emissions part of it'* annual State inspection,.....before going through inspection,.the car was continously throwing up a SES code for an EVAP System Malfunction,........I went out and bought a pocket code scanner and read the code,.....then I cleared/erased the code........the car would go through X amount of 'run'cycles and the code would pop up again,.........just before I had the car inspected I again cleared the code,........NOT GOOD!!.......the inspection station code reader/computer(which BTW is directly tied into a State DMV master database via it'* own dedicated phone line from each inspection station to the DMV server,which records YOUR particular car-specific emissions information AND can detect a hole in the system as little as 0.020 of an inch in diameter.........which I didn't know beforehand ),....the DMV'* computer printed out that the car failed emissions control portion of the inspection because 4 separate areas on the car were 'not ready' to be read,......the Inspector said to drive the car around for a few days to get some run cycles/miles and bring the car back for another check,.....4 days later I took the car back.......and everything must have passed because they put an inspection sticker on the car,......I didn't ask many more questions of the inspector,........BUT there'* not one thing I did to fix the leak/malfunction...and the SES light has since come back on again.
I would like to fix the system(maybe it'* just the one-way valve in the gas cap that'* bad?!?),sometime at my convenience,but I would like to know how many parts the system contains.Thanks for any input/feedback........

You really should list the codes that are popping up. This would help us pin point the area that you would need to look into. Many times, the EVAP codes are a direct result of the gas cap not being tightened all the way. I always turn mine until it clicks atleast 3 times. That way I know it'* down tight. It is quite possible that you have a faulty gas cap, and that is an easy fix.

To be sure though, please list the exact codes that are being stored in the computer.

The one and only code that triggers is P0440 Evap Emission Control System Malfunction........which tells you a whole lot about nothing,..as there are(according to the manual I got with the Actron OBDII PocketScan Code Reader that I purchased)no fewer than 28 other codes that relate to the EVAP system and that are more trouleshooting informative,that break the 'malfunction' down to particular areas/components.

Bill, the major components that make up the evap system are: the evap canister, purge valve, vent valve, pressure transducer (on fuel tank) and inter-connecting hoses. In real simple terms, the pcm runs a routine to check the strenght & tightness of the evap system and to purge the evap canister. Vacum is applied to the fuel tank via the purge valve. The intake manifold is the source of vacum. The pcm must see the system hold vacum. If the evap system does not hold vacum, then a dtc is generated. It is a check of evap system integrity. The gas cap could be at fault here, or there is a leak somewhere else in the evap system.

I would try replacing the EVAP Purge solenoid located on the top of the canister. Also buy a Chilton'* manual # 28200. They have great coverage on the emission'* systems.