engine code p0440

[elocmj]

I have a check engince light on and went to Auto Zone where they told me it is a p0440 code. Which means "The PCM has determined that a malfunction exists in the evaporative emission control system." I would love to know how to fix this. My guess is that an O2 sensor went out. Any ideas?

[Flatrater]

It has nothing to do with your O2 sensor!! Quit guessing on parts you will just throw your money away!! First off all is your gas cap on tight? 80% of all Evap codes are caused by the owners filling the gas tank with the key on or leaving the cap loose.

The evap system checks for fuel vapor leaks, It is a government regulation to monitor for any pollution coming off a car.

If the gas cap ins't loose then you will need to take it to the dealer and have them use a smoke machine on it to find the leak. Don't get hung up on taking it to the dealer it will end up costing you less than if you start throwing parts on it. Afterall you wanted to throw a 100 dollar sensor on your car without even knowing what that sensor does or what the evap system does.