Mishimoto 18+ Audi B9 S4/S5 Baffled Oil Catch Can- PCV SideGive the 3. 0T TFSI powering your 2018+ Audi S4 or S5 the extra layer of defense that it needs with the Mishimoto Direct Fit Baffled Oil Catch Can. Volkswagen and Audi were on the front lines of the direct injection revolution, which means they were also one of the first to implement a means to protect against blow by gasses. While the factory AOS system does filter out some oil and fuel vapors, the harmful contaminants still make their way to the