Blow-by is an unavoidable side effect of forced induction. When pressurized gasses are recirculated through the PCV system, oil particles are carried in that air which causes your intake system and intake valves to become coated in oil. Over time this can lead to carbon buildup on valves and reducing octane levels in the combustion chamber by introducing oil to the air/fuel mixture. Direct injection engines, like the FA24DIT in your 22+ WRX, are extremely prone to harsh carbon buildup on intake valves. The Mishimoto Baffled Oil Catch Can helps prevent these issues by separating that oil mixture from the air being returned to your intake system. As air enters the catch can, it flows through the 50-micron bronze filter followed by the air diverter baffle, which helps capture those oily particles and allows them to condense until they become heavy enough to drip into the canister to be collected. This leaves the air flowing back into your intake system clean and ready to be burned again. The kit includes a billet 6061 aluminum can with black CNC-machined aluminum fittings, a direct-fit steel powder-coated bracket, pre-formed application specific hoses, and all required hardware for a clean and tidy installation. This makes maintaining your 2022+ WRX system a breeze, as the can is also 100% washable, so you never have to worry about replacing the filtration system. Our catch cans are different from most air-oil-separator (AOS) systems. Our catch cans are not heated. This means that all the blow-by can condense in the can, including low-octane oil vapors and contaminated fuel vapors. Most AOS systems drain the blow-by back into the oil pan, while our catch cans trap the blow-by and keep it out of the engine permanently. If you've seen what we've seen in the bottom of our catch cans, you won't want that draining back into your oil either. As with all our products, this catch can kit is backed by our signature Mishimoto Lifetime Warranty.