Infrequent P0455 now comes back soon after cleared. Replaced fuel cap. Put up on rack, none of the hoses are cracked or brittle, but a thin layer or dried hose sloughed off. It is the two cannister running loss system.
Am I correct that the canister close valve is normally open (open when not energized)?
Am I correct that the EVAP canister purge valve is normally closed (closed when not energized)?
Going to start by checking valves.
If valves check out, going to smoke test (cigar and pump). Has anyone done this? From gas tank or from hoses under body?
Not seeing replacement rubber hoses for sale. If replace hoses, what kind of generic hose can I buy the foot?

 

I had this same issue after replacing all the other causes of the 455. Those actions minimized the reappearance of the 455, but maybe after 6-8 months it would popup. After replacing this, its now been 3 yrs and no 455.
Just replace the valve, its cheap and takes about 20 minutes....most of it getting under the car. You'll see more of the condition of your hosing then. Its behind the RR wheel section.

 

Pulled off canister control valve. Bench tested with 12V. At first hardly audible click and valve stayed open with power. Washed out with WD40 and tapped a bit. Solenoid started working again.

 

We had a shop full of cars 'back-in-the-day for CCV faults.

 

P0455 gone. P0442 (small leak) came up 20 minutes into drive. Cleared and didn’t come back in 40 min drive. Crossed fingers.

 

Used a smoke generator to find leaks. (See my post on how to make a homemade one.) Turned out leak coming from both charcoal cannisters because o-rings dried out. Replacement o-rings fixed.

 

Can we obtain a NEW CCV these days? Most of what I have found is pre-owned.
There seems to be a Range Rover/Land Rover alternative but it does not look the same.