***Update***P0456 Cleared - Emission Inspection Passed for 2006 LC (1 Viewer)

[WaHoo]

I am in the middle of troubleshooting (to the extent that I can) a P0456 CEL, I searched the forum and found this thread, Diagnosing EVAP system codes P0442 and P0456 - https://forum.ih8mud.com/threads/diagnosing-evap-system-codes-p0442-and-p0456.1254813/.

I feel like I am chasing a ghost...I don't have TechStream, so I took to a shop to assist with the troubleshooting. Here is what has been replaced so far with no luck in eliminating the P0456 code.

• Replaced gas cap (OEM)
• Replaced Purge Valve (Vacuum Switching Valve, the one under the engine cowling)

I didn't get to talk to the mechanic when they replaced the purge valve to ask if they smoke checked, will verify today.

I cannot find the Canister Closed Valve (it was mounted on the drivers fender well in the above thread) and think this might be the next thing the shop wants to replace. Please see the picture of my engine bay. Anyone know where the CCV is located?

This is frustrating and I would just drive it with the CEL, but I HAVE to get an emissions test (thanks Northern Virginia) to renew my registration/tags. Any help, lessons learned is greatly appreciated.

 

[jerryb]

dont let them replace your canister without a smoke test. Pay for diagnostic, not parts replacement. Done preaching.
GTS pics please

edit
canisters are back by the spare wheel, drop it and you'll see all that canister stuff,

 

[jerryb]

i guess to expand further, a ccv might not be the same in the 2006-7. I would guess it's off the canister.
the only related valves I know are the two brownish things by the fuel pressure regulator rail, the two vacuum valves above the starter for the secondary air injection and the one valve hanging off the drivers side air intake.
there are valves off the canister, find info in the why does my fuel boil thesis thread that I can't stand.
if you want PDFs of the manual I could post them. I looked and no real mention of a closed canister valve.
Should be more like purge valve.
search canister 2006 for technical info, and fuel boiling (if you have a spare semester)

 

[WaHoo]

dont let them replace your canister without a smoke test. Pay for diagnostic, not parts replacement. Done preaching.
GTS pics please

edit
canisters are back by the spare wheel, drop it and you'll see all that canister stuff,

@jerryb - they said they did a diagnostic, I will find out more in a about an hour. If I don't get a good feeling with these guys, I am just going to wait a week or two (waiting on my wife's new car to arrive) and take it out to OTRAMM in Virginia. Thank for the offer of the manual, I think I already have it (FSM but for a 2004), solves 99% of my problems. If you have a newer version (applicable to 2006), that would be greatly appreciated.

Here is the GTS...retirement present to myself.

Pretty cool pic of my GTS and an older Targa...

 

[WaHoo]

Okay...The White Rhino (the LC), threw the P0456 code again, it is going back to the shop to smoke test...not sure what else to replace if the smoke test passes. Fingers crossed...if needed, anyone know a good source for the canisters...I hope I don't have to go that direction...

 

[jOnathN]

I believe your 2006 is the same as my 2004. If so, there are three VSVs (at least):
1) Under the hood, under the engine cowl right near the intake plenum: 25860-50100
2) Under the hood, next to the driver's side fender... this one is connected to the (1) by a vacuum pipe: 25860-50150 (pretty sure but not 100%)
3) Above the spare, attached to the front of the charcoal canister: not officially available separately but included with canister 77740-60440 (plus some bolts and clamps)

That said, I don't see (2) in your under-hood picture... maybe a different setup for 2006 or different part location? I'm tracking a similar problem as it happens, although only code P2418 at the moment, which is meant to be that VSV purge at the canister, so I bit the bullet and ordered a replacement.

One other thing: you said code P0456? That is for an evap system "small leak" - I would bet on the gas cap (maybe a cracked vacuum line) rather than a bad valve. I've had the front valve go bad and it threw a "massive leak" code. Try wiping the rim of the gas cap with a little gasket dressing (I use Hylomar HPF) and reset the code. Or give the rim of the fill pipe a good sanding with 400 grit or something... they can get a little rough from corrosion and fail to seal even with a new cap.

Coincidentally, I am also in NoVa and my play car is a 964 Targa

Good luck!

 

[WaHoo]

Well, I had to bite the bullet and buy a canister ($625) and a canister filter ($115)....I certainly hope this fixes the issue...I took it to two different indy shops. The first one charged me $350 and just replaced the purge valve...light came back on. I stopped in to ask if they had smoke checked it, at first they said no, then yes. Well, you just lost all my confidence in you with that...so, I figured it was worth another $180 to verify and that is the consensus...funny thing though, I ask "what happens if I spend this $1600 and the light comes back on...", they didn't have an answer. So, I can source the parts from a Toyota dealership and install them myself...saves $800. The only downside is that I don't have any recourse if I do it myself.

To make matters worse, I live in a "emissions check" area...my emissions check is expired AND my tags are expiring...I am pretty sure it is b/c I have let my wife drive it for the last few months....

I am frustrated right now...I am usually pretty good at finding issues with the LC, this one is a ghost...

 

[JAntosch]

Likely too late for you @WaHoo, but for posterity I had a similar set of codes and replaced the canister check valve w/ 25860-50100 (same as the one near the engine once the charcoal canister was moved to the rear) ~5 years ago and have not had an issue with the code returning. It was mentioned as functionally interchangeable (for the most part, zip tied in place) in some other thread that I've lost over the years, maybe by onur? I'll be replacing my charcoal canister when the weather improves due to potential saturation/fuel boiling at altitude known issue, so YMMV

 

[WaHoo]

Likely too late for you @WaHoo, but for posterity I had a similar set of codes and replaced the canister check valve w/ 25860-50100 (same as the one near the engine once the charcoal canister was moved to the rear) ~5 years ago and have not had an issue with the code returning. It was mentioned as functionally interchangeable (for the most part, zip tied in place) in some other thread that I've lost over the years, maybe by onur? I'll be replacing my charcoal canister when the weather improves due to potential saturation/fuel boiling at altitude known issue, so YMMV

Thanks man...yeah...I am just going to replace all of it...just hoping the code doesn't come back.

 

[WaHoo]

Well, I replaced the vapor canister and vapor canister filter today...pretty easy, here is hoping the P0456 codes stays away...not sure what to do if it comes back.

 

[WaHoo]

Annnnd the P0456 code is back...dang.

 

[WaHoo]

So, when the P0456 code came back, I was pretty much done...out of options. So, I wanted to try one last thing - checking all the connections and hoses and replacing the aftermarket purge valve with an OEM one. So, every piece of hardware associated with the EVAP system has been replace short of the hoses and lines (gas cap, purge valve, EVAP canister, and canister filter - all OEM). When I visually inspected the system I didn't really see anything that looked damaged or worn. When re-assembling I put some O-ring lube on all the connections and cleaned up the gas cap filler neck with some 1000 grit sand paper. I cleared the codes and drove it for a few days and took it to the inspection station fully expecting them to tell me the system had done the "self-checks".

Well, I was wrong...it passed. I can't tell you the one thing that was done that might have fixed it, but I am inclined to think it was reseating all the hoses and connections. Bottom line, it is fixed, car is legal to register and I don't have to worry about it for at least 2 more years, and I have a new emission system on the White Rhino.

I still have the canister and canister filter and I believe they are good based on the code getting thrown after I replaced them...so, if anyone is interested and wants them, I willing to let them go if someone wants to pay shipping. Just PM me, if you are local, even better.

I have to say, I have done a LOT of work on cars in the past and this was one of the most frustrating malfunctions I have ever tackled...glad it is gone.