Fuel Line Vent Value/Vent Tube Mystery

[Eric Van Kannel]

I have a 2000 Boxster 2.7L with CEL and recurring P0455 error code.  Other symptoms included trouble filling with gas and the howling noise from the filler/right front fender area at shut down.   After some research here I pulled off the wheel and liner to inspect the EVAP system lines and hoses, thinking I would probably need to replace the fuel line vent value.  What I found was the vent tube that runs from the fuel line vent value to the charcoal canister had cracked and broken off where it meets the blue vacuum control valve.  The problem/mystery is that my vent tube is not the same as I see in every parts diagram and help tutorial I can find.  Those diagrams show the vent tube  (part 996-201-255-09) as a direct connection between the fuel line vent value and the bottom of the charcoal canister, running vertically against the canister.  My vent tube runs horizontally along the fuel filler neck to the vacuum valve and then joins another tube in a T connection behind the filler neck.  One end of the T connection runs back up the filler neck to the top of the charcoal canister and the other continues along the back of the filler neck and disappears into the wheel well.  

 

So, my questions are:

Does anyone know why my car is different?

What is the part number for the vent tube I have in my car?

Is this something I can replace myself?

 

Thanks in advance.  Any/all help is appreciated.

 

 

[Loren]

There is a TSB for this problem (TSB 2015 Fuel Tank Hose Modification 3/99).

You should check with your dealer to see if this has been done on your car. If not, they should do it for free.

[Eric Van Kannel]

Thanks for the quick reply.  I don't see the STB listed on any of my service records so I'll check with the dealer as you suggested.  Does this TSB change the configuration of the EVAP system hoses and canister to match what I'm seeing in parts diagrams?

[Loren]

Probably not - the evap system design changed through the years and some of the early systems are likely not available anymore and must be upgraded when repaired.

 

The TSB is really about the proper routing of the hoses to minimize vapor trapping and create the proper venting.