Here’s your edited version with improved grammar, clarity, flow, and consistency while preserving your technical tone and structure: Why would you need an oil catch can system on a modern direct-injection engine? When OEM crankcase ventilation systems fail, they can allow excessive amounts of oil vapor to enter the intake manifold. This not only leads to intake valve contamination and poor sealing, but also contributes to a range of other issues. Another common problem is oil vapor entering the combustion chamber, where it can foul spark plugs and affect piston ring sealing. This is not the type of outcome we want from a performance engine due to a compromised OEM emissions component. To avoid these issues, installing a better-engineered crankcase ventilation solution—such as a dedicated oil catch can—can help maintain, and in so...