Installed a catch can on my Northstar STS Caddy. Because of the rebuild on the motor and the increase in crank case pressure started getting blow back that is when due to high cylinder pressure in this case 13.04.1 comp it will blow fuel and burnt fuel gasses past the rings and into the crank case. To much pressure there can blow throws gasses and oil into the intake manifold to be burnt (not a good thing) via the PCV valve . This will catch all that crud so u don't burn it and or foul plugs, high rpm misfires all kinds of crap. Get one if u race thank me later. Bassonmyfriends