Check Engine Light P0455, P0441, P0456

[RedStickHam]

This morning when I started up my Yaris, the Check Engine Light was on. When I got home, I pulled out my OBD2 reader and got these codes in this order.

P0455
P0441
P0441
P0455
P0456

One thing I did do was remove the gas cap and put it back on before driving home, but the light stayed on. Some of my research has already indicated it could be the gas cap, but there are other things it could be because these codes are related to Evaporative Emissions Leaks.

In December at my last inspection, when the gas cap was pressure tested, it failed, even though the check engine light was off then. They sold me a new gas cap for $10 and renewed my inspection for another year.

The car isn't running any different than it normally does, no strange noises, hesitation or anything like that. The car is a 2009 Yaris Hatchback 5spd with 34,000 miles on it.

Anyone else had this problem?

RedStickHam

[yaris4062007]

Reset it with scan guage , my minivan check engine light comes up i just reset it. Car runs normal :).

[YarisSedan]

Well resetting it wont make the problem go away it just resets the computer and the system monitors the problem is still going to be there and the light will eventually come back on usually about after 100 miles of driving when the evap monitor is set again.

I noticed you stated that they sold you a gas cap. Id highly recommend getting a oem one from the dealer as some of the aftermarket ones are universal and designed to fit multiple cars and sometimes can cause problems still even when they look good and tight as a place to start if you have evap codes.

[CTScott]

That series of codes indicates that the system lost pressure while doing the evaporative check that the system initiates when the car has been powered off for 5 hours.

It very well could be the gas cap, but also could be the Purge VSVm or the canister itself, or the lines between the VSV (under the hood) and the canister (at the rear of the car).

You won't see any obvious effects, as this whole thing is purely a vapor recovery system, and unless the primary vacuum hose to the VSV fails, you will never see it effect how the car runs.

[screenprintr]

Time to check the Canister. Check the holes around it first.

[bronsin]

That series of codes indicates that the system lost pressure while doing the evaporative check that the system initiates when the car has been powered off for 5 hours.

It very well could be the gas cap, but also could be the Purge VSVm or the canister itself, or the lines between the VSV (under the hood) and the canister (at the rear of the car).

You won't see any obvious effects, as this whole thing is purely a vapor recovery system, and unless the primary vacuum hose to the VSV fails, you will never see it effect how the car runs.

So it wont hurt the car to run it? :iono:

Is it true most of the error codes wont hurt the car if not fixed? :iono:

What error codes should we be worried about in terms of dammaging something? :iono:

Thanks!

[CTScott]

So it wont hurt the car to run it? :iono:

Is it true most of the error codes wont hurt the car if not fixed? :iono:

What error codes should we be worried about in terms of dammaging something? :iono:

Thanks!

Correct - That slew of codes will not prevent you from running and you will only "hurt the environment" by running with them.

Codes related to anything other than the evaporative emissions system would be ones you would worry about.

[RedStickHam]

Update:

I drove the car on Saturday and Sunday and it ran fine, but the light stayed on. This morning I started the car up to drive to work and the light was off. I wonder if the gas cap just didn't seal properly last time I filled the car. I had filled the car on Wednesday of last week and the light came on Friday.

I may have flakey gas cap and probably should replace it with an OEM gas cap. Nice to know it isn't too serious.

RedStickHam

[autoexpert1]

Hi,
OBD2 is the best tool to find error codes..
Now after this you should check engine codes details...