UGH P0456!!

[yaris2010RS]

so i officially hate this code! it has been the only issue on my moms 2001 camry and now my yaris has it.

i know its defined to a small leak detected in the evap system. and no its not the gas cap (like was on the camry many many times), it came on once before when i was just under half a tank and now again this morning (just under 3/4 tank)

does anyone have a good place to start checking for an issue? i find it only happens after the car has been drenched with water (first time was the morning after a car wash that night and this last time was after a wicked rain storm all night) could it be an electrical issue or is this just coincidence?

after searching the fourm i know a few other members have had this code come up, what was the route of the cause?

[CTScott]

It can be:

-Fuel cap (loose)
- Leakage from EVAP line (Canister - Fuel tank)
- Leakage from EVAP line (Purge VSV -
Canister)
- Canister pump module
- Leakage from fuel tank
- Leakage from canister

Is this happening on your 2010?

[yaris2010RS]

yep its on my 2010..... i want to take it to the dealership but not sure if it could have been caused by any of my mods (header)

this weekend i will remove header and intake and take it in if i cant find the issue

[CTScott]

Not the header, but check the vacuum purge valve hoses that are by the intake.

[yaris2010RS]

by the intake or on the intake? (run near it on connected to it?)

could water be the issue here? maybe on purge valve?

[CTScott]

by the intake or on the intake? (run near it on connected to it?)

could water be the issue here? maybe on purge valve?

On the OEM intake it is the cube that is attached to the intake tube, near the MAF sensor. It has two vacuum hoses and a connector going to it. I would start there and work in both directions checking the vacuum hoses.

Water wouldn't cause the 0456 unless it's water getting into fuel overflow and plugging up the charcoal canister. There was a TSB on that issue on 07's, but that was fixed by 08.

[yaris2010RS]

On the OEM intake it is the cube that is attached to the intake tube, near the MAF sensor. It has two vacuum hoses and a connector going to it. I would start there and work in both directions checking the vacuum hoses.

Water wouldn't cause the 0456 unless it's water getting into fuel overflow and plugging up the charcoal canister. There was a TSB on that issue on 07's, but that was fixed by 08.

i will check the cube and hoses. if it doesnt come on in the morning i will go back to the coin wash and hose it down and see.

would a kinked hose cause the 0456? or would it have to be a leak? under what conditions does that line have a vacuum in it? (while engine is running or after engine is off it stores the pressure?)

[CTScott]

It gets measured 5 hours after the vehicle is powered off. A kink wouldn't do it, it has to be a leak.

Leak detection pump creates negative
pressure (vacuum) in EVAP system and
EVAP system pressure measured.
Reference pressure measured at start
and at end of leak check.
If stabilized pressure higher than second
reference pressure, ECM determines
that EVAP system has small leak.

[yaris2010RS]

lol so its not as easy as turning the car on and feeling for a leak. lol

it consideres it a small leak so ill never find it. look like header and intake are coming out and its going into the dealer ship

[CTScott]

lol so its not as easy as turning the car on and feeling for a leak. lol

it consideres it a small leak so ill never find it. look like header and intake are coming out and its going into the dealer ship

Definitely not an easy thing to trouble shoot, unless it is just a loose fitting vacuum hose.

[yaris2010RS]

Definitely not an easy thing to trouble shoot, unless it is just a loose fitting vacuum hose.

lol, i know if u say its not easy to do im not even gonna attempt it.

are you sure there was a TSB on the 07? i searched but couldnt find anything

[CTScott]

It is T-EG048-07, but it is not for DTC P0456, it is for DTCs P043E,
P043F, P2401, P2402, and P2419.

[yaris2010RS]

HA! and i dont have those so its off to the dealer i go :p. only thing is ill need to wait till i get a chance to take intake and header out.

so the computer only scans the evap system 5 hours after the car has been turned off? so as long as i resist the urge to go out tonight in the morning the system would have been tested? (i can confirm this after with my scan tool and it displaying a run in relation to the evap) and if its not on in the morning that means i have a intermittent leak?

[CTScott]

Correct.

[yaris2010RS]

OMG THATS SO GONNA SUCK!!!! i really hope to god its either on in the morning or never on again.......

thanks CTScott for all your help

[yaris2010RS]

so this morning the engine light was not on. i ran the scan tool anyways and found the car had not run the evp system check over night(probably due to the c02 check not being preformed while i was drived the night before)

im now at school and its another +5 hours till i go out to my car so i will see then if the check was run and if it passed or not.

just thought id give a quick update

[yaris2010RS]

since no one ever does this, ill update this.

*****issue seems to have been resolved, anyone with a after market intake should check for this*****

44252

apparently the Ziptie i had used to hold the purgevalve in place failed and the entire thing fell to where my shifter linkages were and when it got hit it cracked.

this part is 139.99 from the dealership (i got one free off a wrecked corolla which is a different part # and looks different but it seems to be working.)


when i get home from school today i will post picks of the old valve and hopefully tonight the computer will run the evap test and throw no codes

fingers crossed

[jemmah]

I've got a 2007 Yaris with 200k miles. I've had a p0456 code twice over the years. Both times I OVER filled the fuel tank. Both times the code would show up the next morning. If you over-filled this could be the problem. Please check this situation first before you start tearing everything apart!! I assume there was fuel flow into the charcoal canster and the by-pass opened.