P0456 fault (1 Viewer)

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lxid

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Of course go to toyota free ski day and when I leave the "check vsc system" and a bunch of other lights are on. Pulled the code and it showed P0456, Evaporative Emission Control System Leak Detected (very small leak, check fuel cap, piping, etc).

Haven't done much yet other then making sure the fuel cap is tight. Any other ideas what I should check? Truck seems to drive fine. Was a little worried the VSC wasn't going to be working coming down the mountain, but seemed fine.
 
lxid said:
Of course go to toyota free ski day and when I leave the "check vsc system" and a bunch of other lights are on. Pulled the code and it showed P0456, Evaporative Emission Control System Leak Detected (very small leak, check fuel cap, piping, etc).

Haven't done much yet other then making sure the fuel cap is tight. Any other ideas what I should check? Truck seems to drive fine. Was a little worried the VSC wasn't going to be working coming down the mountain, but seemed fine.
Click to expand...

How old is the gas cap/gasket? Might be time for new one. Was the ski trip high in the mountains, with lots of elevation change? Is the dash light still on, or did it go off after driving for a bit (once you tightened the cap).
 
Not sure how old cap is, probably original 2008. Only 2-3k change in elevation. Light is still on haven't cleared it yet. Probably try to clear it and see if it persists then order a new cap I guess.
 
At least two of the evap leak club members (including me) have already replaced the gas cap to see if it made a difference.

It did not.

Heck, @Atwalz even replaced his canister.

No change there, either.

So at this point, I still keep my reader handy and regularly have to clear the Christmas lights on my dash.

No idea why the 4Lo and other lights turn on, as my 4Lo shifter works juuuust fine...but that's what it likes to light up...among other colorful doodads.
 
Oh this is sounding like a fun one. So no one has been able to find a fix? Anyone taken it in to toyota?
 
lxid said:
Oh this is sounding like a fun one. So no one has been able to find a fix? Anyone taken it in to toyota?
Click to expand...

Oh it's "fun" alright.

But this thread doesn't even mention the most "fun" & weird fact...that being that 3 of the 5 trucks that drove up Top of the World Trail in Moab...and "boiled" gas in our tanks...all ended up with the same codes and issue immediately upon return home. @TonyP, @Atwalz and myself.
 
I took my 200 to the dealer, big shocker, they had no clue and told me to replace the gas cap.

The best solution (or road to a solution) is getting the evap system smoke tested. A proper smoke machine isn't cheap so buying yourself isn't feasible. You'll have to call around to shops to see if they have the emissions leak smoke testing machine. I've just been remarkably lazy and haven't gotten around to doing it myself. Clearing the code every couple of days is much easier.
 
I haven't had it up very high recently, but did a lot of wheeling this summer in the mountains. I did get pushed off our county road by a snowplow the other day. Snowing so hard couldn't see the edge and he gave me no room. Got sucked in pretty deep into 2-3 feet of snow. To my surprise it drove out, but wonder if some of that hard snow could have did something.

What an annoying problem to have. Has anyone tried the smoke test?
 
My cel code numbers are different. Yours may be related to gas cap only. Ignore P1604.

A83F2CD4-BF18-4012-98B6-DB42D169390C.jpeg
 
@TonyP , @Markuson
Are you getting the same codes as Kamal?

Looks like the test pump valves are stuck.
I've seen a couple 570s being parted out on eBay. Maybe we can get some components cheaper and start testing. Or smoke test and find parts cheaper.....doubt any 570s made it to the top o' the world;)
 
Markuson said:
Oh it's "fun" alright.

But this thread doesn't even mention the most "fun" & weird fact...that being that 3 of the 5 trucks that drove up Top of the World Trail in Moab...and "boiled" gas in our tanks...all ended up with the same codes and issue immediately upon return home. @TonyP, @Atwalz and myself.
Click to expand...

My fuel was boiling but not quite leaking out of the truck yet. Never had any codes though but my gas couldn’t have been in that state for too long since I didn’t drive all the way up.

A couple thoughts occurred to me recently while I was at Valley Hybrids observing the aux tank R&D as occasionally codes would come up and need to be cleared as system components vented to atmosphere.

One, there’s something about how often the ECU runs emissions tests upon when the vehicle is started and when it’s in accessory mode. Just thinking whatever that interval is may explain why the codes pop sometimes but not others?

Second, and maybe more promising, is that codes can be triggered by almost negligibile amounts of venting. This is a total guess, but I wonder if the combination of increased pressure in the system and off-road driving compromised a fuel line connection, sensor, etc.? To Tony’s point a smoke test would check against those mechanical issues but not if something electrical wasn’t working (not sure how else you’d verify that aside from doing the smoke test first).
 
TexAZ said:
@TonyP , @Markuson
Are you getting the same codes as Kamal?

Looks like the test pump valves are stuck.
I've seen a couple 570s being parted out on eBay. Maybe we can get some components cheaper and start testing. Or smoke test and find parts cheaper.....doubt any 570s made it to the top o' the world;)
Click to expand...


I think so. Can't remember the code number exactly but it was definitely "Evaporative Emission Control System Leak Detected".
 
Since they pop up every 3 days, can the collective members having this problem post the list like Kamal did. Will be interesting to see if there are any differences. Mine should pop up tomorrow. I'll post my results.
 
camino70 said:
Reviving an oldie.

Any pertinent updates?
Click to expand...
Reviving the revival, anything new? Got the p0456 on my ‘08 LC, mechanic is unsurprisingly eager to replace the evap canister…
 
Been a minute since we visited this issue. I got lucky and found a used cannister on ebay. Rolled the dice it would work. I get codes every now and again, but generally that fixed the issue. It's a super easy replacement. You could save some coin going that route.
 
I just got the P0456 code.

I was getting the P0441 code at the beginning of the year and had my charcoal canister replaced back in April. This cured the P0441 code. I also replaced the gas cap, at that time.

I just purchased a new cap on Amazon in the hopes that it fixes this issue.

But has anybody found a good solution to it other than just clearing the codes?

I will add that a couple of days ago in the morning I got the “check gas cap” message. I did and it seemed fine and after checking it the message went away.
And then this morning I was greeted with the check engine light and the “see your dealer” message.

I do wonder if it’s weather related since these have been the first “cool” weather we have seen in Houston (low 50’s).
 
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