Fuel tank overfill

[Box C]

When I bought my CrewMax the salesman cautioned me about not overfilling the fuel tank by squeezing the last few drops that I could get out of the pump. He said that this would cause raw fuel to enter the fuel charcoal cannister and this would cause the vehicle to fail emission control testing. This sounds a little far out to me. Has anyone heard of this before or had any experience with this?

[3urfe]

i dont listen that so I recently overfill mine and smell gas

[wildbill129]

It's true, it was mentioned in another thread. Let me see if I can find it.

[guntech]

I just had to have that cannister replaced in my Camry.

[Charley_S]

I think this is true for most new cars these days.

We have a Subaru Outback ('02) and I recall when we bought it that they made a point of telling her/us never to "top off" the tank.

[djb383]

I've always heard that clicking the nozzle over and over to get the last drop in the tank could damage emission components. When the nozzle shuts off the first time, I call it good.

[jkd]

He said that this would cause raw fuel to enter the fuel charcoal cannister and this would cause the vehicle to fail emission control testing. This sounds a little far out to me. Has anyone heard of this before or had any experience with this?

I've read it in shop manuals, etc, for at least 20 years, nothing new, and it's true.

[Tundra Man 2007]

Let me get this straight, there is a filter in the gas tank that is harmed by gas? Isn't that, I don't know..............stupid.

[crankytexan]

Let me get this straight, there is a filter in the gas tank that is harmed by gas? Isn't that, I don't know..............stupid.

I think it is meant to capture the fumes as they exit the tank and recirculates them The actual contact with gas, something that it was never meant to be touched by, causes the issues.

Not that that doesn't make sense as to why you would install something that is destroyed by gas so close to gas.

[jkd]

It's not stupid or in the tank. If you do some searches you can probably find where they're located and what their function is. They've been standard equipment on gas engines since the mid '80's at least. The canister controls gas vapors, but filling it with raw gasoline ruins it---big difference in the two.

[fla_guy]

I'll add another one to the heap - it is well known not to fill the tank like that. And like jkd said - it is not stupid or in the tank LOL! Salesman was telling you something you should know anyways. Plus when you do that you are more likely to spill it on the ground and pollute.

[Negra]

I frequently fill my tank to where there is literal fuel above the tube flap (extended running for long trips)topped off deluxe if you will.
I haven't had a single issue with throwing codes or anything ......

[Frankenstein]

Maybe so, but mine is showing the check engine light right now, and has been for the last week or so. I might have overfilled it before this happened. I went to the dealer today but they were too busy, said I could go by in the morning. What fun.

[96T100]

its true. i have replaced may charcoal canister on camrys because people keep on clicking more gas into their gas tank. it will fail your emission because the check engine light will come on for an evap. code.

[techenigma]

Yup its true. The charcoal canister on my 4Runner needed to be replaced before because I always topped off. It happens because when you over-fill and the fuel system gets pressurized the gas will flow up the fill neck and spill over into some vent holes on either side inside the fill port. These are vent holes that lead to the charcoal cansiter hence it fills with gas and eventually ceases to function. The emissions control will then cause a check engine light, and the code displayed will indeed be for the emissions control error. It look nearly 18 months of topping off to finally do mine in.