Long story short, my dealer said that this tube was essentially telling the ecu how much oxygen its getting. However Im pretty sure its just to remove excess gas from inside the rocker cover. I have replaced the tube with two mini pod filters; primarily because the tube that came with the intake was getting pinched and was rubbing the paint off the injector cover.

What it normally would look like:


My mod:


Is this tube essential? Or can it be tossed aside?

 

You pretty much got it, it's a breather. It takes any vapor present in the valve cover and reroutes it back into the intake tract to burn it off. Helps but is not 100% necessary. And the dealer is full of it. The ECU gets an O2 reading off the O2 sensors. There's not even a sensor on that hose going anywhere! It's intake to valve cover, that's it. No wires, no sensor, no connections.

 

Dude, that tube is important! It is used to remove blow by Hydrocarbon (fuel) from the crank case. Every engine has blow by, created from the compression stroke, where the air and raw fuel are compressed just before the power stroke or ignition. A small percentage of the compressed gases Will get past the rings and enter the crank case. If the blow by is allowed to accumulate in the crankcase it could eventually dilute and contaminated the engine oil thereby creating sludge!....It is part of the PCV system.

There is another sensor very close to that area, (the MAP sensor) used to measure the vacuum in the intake chamber. This information along with the throttle position and RPM are used to calculate the amount of air entering the engine.

 

It's a breather, what you really should do is put a catch can in that place. Then you wouldn't get that nasty oil smell and it filters the oil from the intake.

If you don't want a catch can, I'd just cap the pipe coming off the intake, you don't need to put that filter on there.