The Oil Catch Can in the car, its main benefits are: It prevents oil vapors from reaching the intake manifold (throttle and manifold). It reduces carbon buildup and deposits inside the engine. It helps keep spark plugs and intake valves clean for longer. It may contribute to stable engine performance over time. It collects oil and moisture from the engine's crankcase ventilation system (PCV) instead of re-entering the engine. However, if the engine is in good condition and usage is normal, installing an oil catch can is not always necessary, especially in modern cars like the Toyota Camry because the ventilation system is designed to work without additives.