2001 Intrepid "P0455" Evap Systems Leak

Hi All,

Just joined and this is my first post. I have an interesting one here - hopefully someone can shed some light on this for me.

I got the "P0455" code for an evap systems leak on my Intrepid . I did the normal extensive search for a broken line, checked the fuel cap and came up empty. I then reset the code and began looking for some pattern. Here is what I found.

The MIL (P0455) only comes on when the fuel tank level drops to 5/8. At that point, if I reset the code, the MIL stays off until I refill the tank above 5/8 and let it drop back down to the 5/8 level. The MIL wil stay off as long as I keep the level below 5/8 or fill it above 5/8 and keep it filled above this level. So, there is some event taking place when the fuel level drops to 5/8 that causes the MIL to illuminate. Also, If I do not reset the CODE, the MIL will stay on regardless of tank level.

Anyone have experience with this condition who can tell me what may be the cause? Thanks in advance for your input.

Steve