Originally Posted by StingRay
Eh, I haven't seen any long term reviews to have much of an opinion on it for the focus specifically. But it will probably be one of the first mods on mine when I get it. Even on the NA focus there was a good bit of oil residue in my intake, the increased crankcase pressure on the ST can only make that worse. Plus direct injection engines have enough of an issue with buildup on the valves, might as well install something that can help reduce that even a little bit! Just my opinion though.
Env laws, so car makers dont let that oil discharge to the ground. Oil dumped into the intake will go into the turbo, causing damage in the long run. in my old car it was so bad it would soak the turbo wheel in oil, creating fluttering. the breather on the cold side would direct the oil into the intercooler creating a big mess as well. it would also reach the bov, tb and int mani. When the bov vented you would see oil splattered all over the hood
I ended up using a catch can on the cold side = one line to the pcv one to the valve case and putting a mini filter on the hot side vent, it would eventually leak a bit to the ground. So i would have to clean the oil soaked filter every 2-3 days