Good idea Shayne, thats what I did. I definitely retained the charcoal canister because it actually serves a meaningful purpose and there's no reason not to have one on your car. Basically fuel left over time pressurises in your fuel tank and also evaporates into vapour into the atmosphere and contributes to pollution. When your engine is off the canister releases pressure and traps fuel vapours from the fuel tank inside it, and when you start the car up the vacuum of the intake manifold opens up the valve on the charcoal canister and sucks through the vapours into the intake system. Its a simple system that really isnt going to cause you any grief weight or power wise unless the filter in it is clogged or unplugged. If its unplugged you're gonna smell fuel vapours really bad under the bonnet, and if its clogged or oversaturated with fuel you may experience either a bad fuel smell from split rubber lines, the canister overflow with fuel, or a lot of back pressure when opening up your fuel tank cap. You should really be replacing or cleaning these things out every 40,000kms with compressed air but Im sure most people have never even touched them!