Anatomy of P0456 - Small Evap Leak

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This just started happening to me…
Which is interesting b/c my fuel system is totally stock, no LRA tank, changes, etc..

I may take down the evap canister next week to check it out, probably do a smoke test but I guess I’ll just replace it. I did look at all the fittings etc and saw nothing out of the sorts.

So it’s not just an extra tank thing it seems.
 
for those keeping score...

Charcoal Canister Assembly
Part Number: 77740-60520
Charcoal Canister Filter Sub-Assembly
Part Number: 77706-60050


Both replaced, Gas cap replaced... No change in P0446 code occurrence, next step is to replace
Vacuum Switching Valve Assembly

Part Number: 25860-0S010

and do a smoke test on it. It's an annoying code. but hey all that stuff will be new..
 
prharper said:
:popcorn:
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Ditto. I’ve got the canister in the filter on the shelf, but I’d really just be replacing parts. Guessing what the issue is I’m gonna have to tear into this sooner or later but for now I’m just clearing codes when they pop up.
 
kcjaz said:
Ditto. I’ve got the canister in the filter on the shelf, but I’d really just be replacing parts. Guessing what the issue is I’m gonna have to tear into this sooner or later but for now I’m just clearing codes when they pop up.
Click to expand...
I don’t want to jinx myself but last time I got the code was last April. Didn’t replace anything.
Have new charcoal canister, wiring harness and these two sitting on the shelf.

IMG_8766.webp
 
I would also get the 77706-60050 also includes the hoses, etc.. and is another(?) catch canister.. Replacing 25860-0S010 is a 2 minute job, 1 bolt, 2 lines, job done..
no codes yet..
 
ok so on further review of what the parts actually do vs what the part actually does..
Vacuum Switching Valve Assembly Part Number: 25860-0S010 This is actually part of the Vacuum idle system (i believe) and not hooked into the Evap system, it goes from the manifold to the idle diaphragm. SO if your parts counter tells you this is the correct part, it is not.

What you need is the one in front of it on the engine which is 90910-122276 - Superseded to 90910-TC001 - this IS part of the Eval system. Even though it is called the Duty Vacuum Switching Valve.. this routes from the tank evap system to the Intake manifold (which does create vacuum under load but does not maintain it once the engine is shut off.

Hopefully this solves it for good, since the CEL is causes is annoying, its an electric opening part which can leak over time.
 
And….’it didn’t fix it, But I found the actual problem, so I would smoke test first starting on the engine side, it 20 seconds to figure out once I did that. This tear was on the bottom side of the hose
IMG_0579.webp
 
Nice, what did you use to do the smoke test?
 
rlynch356 said:
And….’it didn’t fix it, But I found the actual problem, so I would smoke test first starting on the engine side, it 20 seconds to figure out once I did that. This tear was on the bottom side of the hose View attachment 4106674
Click to expand...
Nice work Rob!
 
Took me long enough… well at least now I can check off replacing the entire evaporator system prior to doing an extended tank checkbox /)
 
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