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Dan
Dan, Technician
Category: Toyota
Satisfied Customers: 23590
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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Have 08 Toyota Tundra with p455 code. Not gas cap dealer

Customer Question

have 08 Toyota Tundra with p455 code. Not gas cap dealer says it's one of the vacume but says I need to change out canister because the vacume are atached and are part of the canister. Is that right
JA: Have you scanned the code? Have you tried to reset it?
Customer: Still P455. I have not changed anything yet. I can't belevie I need to change the Cansiter if it's not leaking. What would you change.
JA: What year is your Tundra?
Customer: 08 4.6
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Yes. I have not done anything yet. think I need to change one of the vacume
JA: Anything else you think the mechanic should know?
Customer: No
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Toyota Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Toyota
Expert:  Genchi Genbutsu replied 5 months ago.

Thank you for allowing me to help you with this concern today and am sorry to hear that this is happening. I will have to ask you a few questions so that I can get a better understanding as to what may be going on with your Tundra.

The P0455 code is for a Gross (very large) EVAP Leak, have you tried just clearing the code, tightening the gas cap and then seeing if the code returns? This system will check itself every night.

Customer: replied 5 months ago.
Change gas dealer says need to replace canister but it is not leaking there. Says it is on of the value but are attached to canister. So I have to change everything
Expert:  Genchi Genbutsu replied 5 months ago.

It sounds to me like they are guessing at this repair. Let me ask..

Did they smoke test the system to "find" this leak?

Did they offer to show you what is leaking (these hoses) on your Truck?

Customer: replied 5 months ago.
They said it has a bad valve but it is attached to the canister and can not be removed so you have to change everything
Expert:  Genchi Genbutsu replied 5 months ago.

It doesn't sound like you were taken care of at all on this. The way this EVAP system works is to test if raw gas is leaking out into the air. This is emissions and we don't want raw gas just escaping into the atmosphere.

The vacuum pump/canister will draw a vacuum on the system and watch how long that vacuum lasts. Now lets say you left your gas cap loose, the vacuum wouldn't last very long and the system would fail this turning your check engine light on and setting the P0455 Gross Evap leak. This happens every-night your trucks sits for 5 hours or longer.

Does this make sense to you?

Customer: replied 5 months ago.
what should I change to fix the problem
Expert:  Genchi Genbutsu replied 5 months ago.

What I would do, is tighten the gas cap and clear the code (this can be done by using a scantool like from Autozone or disconnecting the battery for 1-2 minutes) then just driving it like you normally for 1-2 days. If there is a true problem, which I doubt there is, then the P0455 code would return back on. I doubt it will. We rarely see any problems out of these system unless the cap was not put on fully.

If you have more questions, please ask as I strive to give Excellent service. Also please take the time to rate my help (1-5 stars), as it helps me as I have just helped you.

Customer: replied 5 months ago.
It is not the gas cap. I put an one on and cleared the code. It came back on after two days. That is why I took it to the dealer for the test I told you I had done. Is the only way to fix this is to replace the canister.
Expert:  Dan replied 5 months ago.

Hello, my name is***** are valves built into canister. If dealership said canister is the problem then I would take their word on it and have it replaced. Here is also information from manual on code so you can see possible causes and testing that should be done. Let me know if you have more questions, thanks.

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https://www.dropbox.com/s/21dxchmc91c7ap3/p0455.pdf?dl=0