Join Date: Dec 2013
Location: Tampa Bay, Florida
Although I have not seen the charcoal vacuum canister on our Elise, that sure looks like one. I have experience with this system on other vehicles enough to know that when the intake manifold vacuum is high (during idle) the vacuum solenoid is closed. It opens under higher RPM's by the ECU which is monitoring (vapor) flow back from the gas tank through an in line flow sensor. This is all balanced by the gas cap seal and the fresh air inlet (on some vehicles, also under solenoid valve control). The fuel vapor recovery system is throttling evaporated gasoline into the intake manifold with the charcoal canister catching any droplets or impurities. Toyota also employs a fuel tank vapor pressure sensor as part of this system. If you bypass it, you may run rich without the ECU's ability to control it. I do know that if the ECU doesn't see flow when the solenoid is open and none when closed, you will throw a C E L (check engine light) within a few drive cycles. There is a list of different error codes that can originate. I hope this helps you.