Replaced gas cap, code went away. Week or so later, p0455 again. Concerning a smoke test, would it be possible to use a food smoker gun? Only drive issue seems, low power and idle low around 650 700rpm..

 

No help here.
I don't know about the smoker, but I'm having the same issue. Found one tube that was cracked and replaced it. Still getting the code. Still digging around.

 

Not a lot of information here. The model year would help as many of these vans have an issue with the fuel filler tube corroding at the top.

 

Heh, thought I had it in my siggy.

For me
2001 Grand Caravan ES 3.6L

 

Trouble spots on the 2001-2007 minivans concerning EVAP codes.


There is a canister hose UNDER the air cleaner that splits. It's where a plastic tube transitions into a metal tube about 2 inches long.


The rubber connector tubes out a few inches from the purge valve will split.


The rubber hoses AT the canister.


Earlier models of this generation also have a small vapor hose connection as you move from the canister back towards the tank about half way in the middle of the van.


NVLD sits right under the left seal of the power steering rack and if the steering rack leaks,(which IS common) it soaks down the diaphragm in the NVLD causing an internal leak, which a smoke test will never find.


A previous poster was correct about the rusted filler tubes. We don't see this in Tennessee, but snow/salt belt vans will do this very often.


Very rarely the purge valve will have an internal leak.
Very rarely the NVLD switch will just plain stop working


The way we find internal leaks, is by using a smoke tester with the option of a ball check pressure test. You can't just use a fog machine because you have to have air pressure behind the smoke to force it through. BUT, you could always rig one up and charge your buddies...hehe.

 

Awesome! Thanks for the excellent pointers. I have a new way to proceed now!
Thanks again!
r