RTMG Performance Universal Oil Catch Can Large 17mm - 0.66in Black - RTMG-901-1316 - One common problem of the direct injection engines is the carbon build-up on the intake valves. Due to the direct injection fueling system, where fuel is sprayed directly into the combustion chamber, the intake valves are not cleaned by fuel, therefore carbon deposits, a product of oil fumes of the stock PCV system, build-up on the valves. The RTMG Oil Catch Can kit can reduce the carbon build up on the intake valves up to 60%. The catch can also prevents oil pooling into the intercooler and intercooler hoses. Our smart three-stage filtering system takes care of the lighter vapors, while it also features a unique direct path to the bottom of the catch can for the heavy oil vapors, resulting in cleaning up to 99% of the returned fumes/vapors. Specifics: CNC Billet Oil Catch Can Monoblock Three Stage Baffling System Oil Level check with a dipstick Drain-in-seconds system with drain valve Serviceable three-piece design AN10 Fittings Reduces Carbon Build Up Small Dimensions & Capacity : 120 x 80mm - 300ml Large Dimensions & Capacity 160 x 80mm - 400ml