I've got a stock xB that keeps throwin a check engine light. It has happened three times so far, and every time it is the same code (P0440). its at the dealer now for their THIRD repair attempt. Any advise?

 

PO440 is an evaporative system malfunction (not holding pressure). It could be anything from a bad or loose gas cap, hose off under the hood, leaking filler neck or anything that could allow the fuel system to not hold pressure. ~~~~~~~~~`scott

 

take it in if you are all stock its a charcoal canister but if you have and intake make sure all hoses are tight and in place ok

 

It is completely stock, they replaced the charcoal canister the first time, and the second time a few evap hoses...at this point it feels like they are just guessing!

 

One of the most common things with car that have that problem is the seal on the filler cap is bad, either from a pinch in it, to a cut, or a flat spot on the seal. Have them check that!!!!

 

thanks for the tips. I just got a call from the dealer. They are replacing the gas cap next and seeing if the light comes back. is it possible this could be a control unit or computer problem?

 

Not likely with the code you are getting!!! :D

 

Although this does not address this particular issue, let me offer you a tip that may save you some grief later on.

After you fill-up with gas make sure you turn the gas cap until it "clicks".

If you don't do this you may end up with the check engine light coming on. If this happens you take it to service and they charge you a minimum diagnostic fee of maybe an hour or so. In the end they tell you to click the gas cap in the future.

 

thanks for the advise. I actually work at in the service department of another japanese manufacterer. we often get people coming in with their gas caps loose, or even missing. So I am very **** about tightening the cap, especially since the light started coming on.

 

When you have a bad canister you usually get just the P0446 code. So I doubt your canister is bad.

Sounds like something with the stupid gas cap.

 

Well, the codes they were getting this time were: P0441, P0442, & P0446. They found no visible leaks after using a pressure tester, and the toyota field tech thought it might be a loose gas cap, so they replaced it and let me go. I talked with a few of the techs from my shop and they think its unlikely all of those codes were just from a faulty gas cap. Anyone have any ideas?

 

When you get the Evap Hat Trick of 441, 442, and 446 I'd say after throwing the code that many times your canister has got to be ____ed.

 

It's definately a leak somewhere. Check the sealing surface of the filler neck for dents or surface irregularities. Some of these leaks can be pretty hard to find, like the top plate on the gas tank, O-ring on the vent hose from tank to cannister, etc. Find a dealer that has a smoke tester for evap systems. This machine fills the tank and system with smoke and small leaks are easiest found with this method. Otherwise, pressurize the system and spray soapy water solution all over everything and the leak will bubble. Pain in the ___ but sometimes it's the only way.~~~~~~~~~~~~~~~~~`scott

 

supposedly, they replaced the charcoal canister the first time i came in...

 

Like clockwork, the light is back on....

 

Take it to another dealership. I had a car once with evap codes that had a brand new canister installed at some other dealership and the idiot who did it forgot to plug in some big imporant hoses on the canister which made it throw codes. Some places just let any idiots work there.

 

well, I took it to another dealership & they got the P0440, told me I had to have left the gas cap loose, wouldn't look into anything else, and charged me for the diagnostic...

I like the car...hate the service I am getting...but, what can you do?

 

Hi, the engine light does not mean anything is wrong. It will go one everytime you start your car. It just means your engine is not yet warmed up,. as soon as it runs for a minute it will go off. In the winter it will take longer for it to shut off because of the colder temperature. I hop ethis helped

 

That would be the blue temp light. If you read the posts he is having abnormal problems regarding an evaporative system malfunction.

 

So...I left the dealership, paying for a diagnostic charge on a vehicle that is still under warranty. They insist a loose gas cap is the only possible cause for the codes (P0440, P0441, P0442, & P0446) stored in memory, and no repair was attempted on the last visit. I left, KNOWING the light would come back on within 350 miles just like the 4 times before. It has been around 2000 miles, and the light hasn't come back on...

So, I am feeling a little uneasy with my vehicle. I think one of two things happened. Either the problem that was causing the light to come on miraculously fixed itself, OR the dealership that I took it to was not being completely honest, and in some way manipulated the check engine light system so that it would not come on.

To test my theory, the last time I filled up the gas tank, I purposely left the gas cap off to see if the light would come on. I went through two full tanks like this, with NO check engine light....

I just worry that something really may be wrong with my car, and I won't be able to figure it out until it is out of warranty.

Is it just me, or does this sound a little fishy to anyone else? Is there any way that I can check to see if the dealer may have disabled any part of the evap system? The light does illuminate when turning the car on, along with all of the other dummy lights.