engine code P0455 after hearing a pop sound under hood

[urbandweller]

I have been working with chasing down the P0455 error code on my 97 855. I can reset the code and it stays off for a while. With the weather getting colder it happens more often. I have noticed that the check engine light with come on just after a i hear a popping sound from under the hood. it happens so in frequently that I cannot get out and chase it when it happens. it almost sounds like a slip in the brakes type of pop. Could this be the valve on the radiator or the trap under the battery?

Any help is appreciated.

[jreed]

I had the same code on my '97 855 GLT and I wrote up a short summary of things I looked into to finally resolve it:

http://volvospeed.com/vs_forum/topic/11 ... ode-p0455/

I've copied my working list of things that can cause the failure below: (Please feel free to add to it)
worn out gas cap (or non-OEM gas cap),
dings on the metal fuel filler neck,
failed seats on the Evap purge valve,
bad check valves,
broken rubber J hoses,
broken rubber connector hoses,
failed seals on the fuel pump and / or fuel sender,
failed pressure sensor in the fuel sender unit