often times it can be the leak detection pump, but it has been known to be the charcoal canister stop performing. often, that can be a result of over filling the gas tank and the overflow falling into the charcoal canister.

 

My small evaporative leak turned out to be a defective check valve within
my charcoal evaporative cannister. The check valve was replaced.

 

so u mean it is Leak detection pump or charcoal canister, i am confused,

how much is that leak detection pump, valve u describe here, also the price of Charcoal canister do u have any idea, also where i can find good price....dealers are very expensive , i wanna try by myself , so far i try checking pipes etc..replaced gas cap but unfortunately no sucess...no leak under tire at pumping location, also i never try to over fill the gas tank , i usually try to leave little space for gas pressure in Tank,never over fill it,

so i can replace those .....

thanks kindly,

 

Late to the party, but another common cause of these evap leaks in salt-belt states is corrosion on the filler neck, and it's not always in an area that would cause a visible fuel leak while filling. The plastic insert at the top of the neck that the cap screws into is just press-fit into the tube, corrosion in this area can allow a vapor leak without any liquid fuel spillage. The junction point with the vent tube near the top of the main tube is another common failure point. Leaks at the neck usually result in a noticeable fuel odor, but smaller leaks can be tough to catch.

Replacement filler necks are readily available from parts stores and online for about $100, but I just wire-brushed mine (off the vehicle, obviously) and covered it in fiberglass 'cause I'm a cheap bastard. Been holding four years so far!

 

We own a 2003 Dodge Sport Caravan Conversion (Entervan) and when the gas gauge gets down between 3/4 and 1/2 it throws this same code about 3 times a month.

I went on ebay and purchased an OB2 code reader and just reset it. I guess one of these days I'll take it to the dealer and have them repair it, the van has 16,500 miles on it and runs fine.

It is a pain, but resetting with the code reader is easier than disconnecting the battery and the built in code system.

I think I paid around $45 shipped for the reader and it works on a wide variety of vehicles.

Just my thoughts.... GG

 

Wish I had a dollar for everytime I've posted this link: http://www.youtube.com/watch?v=CSn0ljUS6kI

 

Thanks for posting the youtube link, Cougar41 !! Even though I don't have a smoke machine to test the evap system for leaks, I found two cracked hoses on my 03 GC under the air filter box, just as shown in the video. These hoses connect to the evap test port shown in your post. Replaced them with some 5/16" hose from AutoZone for $1.29, reset the codes and I'm good to go. Hope this helps someone else.

 

I know this is an old post but I fixed my small evap leak. My engine light came on last week and came up the code P0456 on my '03 Grand Caravan. Checked the obvious locations connectors, hoses near air filter. Found that my pcv valve was loose and tightened it and cleared the codes again. After a very short drive down the street the check engine light came on again. Traced all evap hoses to the vapor canister under the van and pulled off one 3/8 hose off the canister only to find out that the hose split near the connector. Bought a regular 3/8 fuel hose and cut it to length and put new clamps on and slightly tightened them up. I then cleared the codes again and drove the car about 2 miles and no problems with the check engine light. Hooked up OBDII to recheck for any codes and found nothing. Seems to be all okay now. Very simple to fix even a monkey can do it.

Here is what the vapor canister on a GC looks like. It's located on the driver's side under the car. It's big and you can't miss it!!!

http://www.rockauto.com/catalog/moreinfo.php?pk=932968

 

I had this problem with my 02 caravan for two years with the lights coming on and off.. after replacing the fuel cap. went out for about three months and came back on.. replaced the hose under the air box that is connected to the same line that is connected to the service port. trace that back to under and behind the air box there is a 4" elbow that goes from the plasice tube to metal tube and connected by the rubber hose. the light went out for another few months. enough for me to pass inspection.. thank god. then about 40 miles past inspection it came back on and stayed on for almost a year until i found the problem was that the plastic clamps that dodge uses may appear to be on and tight are actually cracked and not holding well not to mention under the power steering resavior there are hose that the fluid leaks on and swells the hoses up and break the clamps.. i bought new clamps and haven't' had a problem with it since. and of course when i took hoses of the LD pump i made sure there was no cracks in them. hope this help solve your problem. as it was driving me nuts in to replacing all that had to do with evap system. less than a $10 dollar fix for me.

 

I haven't yet solved the evap leak problem on a 2003 Caravan. I had PO442 & PO455 codes, small and large leak. I replaced the gas cap with a genuine Dodge part ($33.) but that did not solve the problem.

I then checked the hoses under the air cleaner box; no visible problems there but I replaced the 5/16" hoses anyway. From there, the hoses go to the Evap Purge Valve Solenoid (or Control), which is Wells part no. PV-302 and is available online for $18.00 (of which $8.00 is shipping) from Pollard Mopar Parts in Colorado.

Between the air cleaner box and the Purge Valve Solenoid, is the Evap Test Port, which has a green plastic cover. I found cracks in the hoses there on either side of the Test Port and replaced the hoses--and the test port--with a 6-inch length of 5/16" hose because I wanted to make sure the Test Port was not leaking. After this fix, when I cleared the codes only PO455, the Large Leak code, came back on.

I intend to check and replace the visible hoses under the minivan. If that does not fix the problem, I will send for the Evap Vent Valve, which resides next to the Evap Canister under the vehicle beneath where the drive sits, and replace that. After that, I guess I would have to consider replacing the Evap Purge Valve Solenoid ($50. at AutoZone) and, perhaps, the Canister itself ($133. new but I would try to find at the junkyard).

Any other suggestions will be well appreciated.