HEMIs get blow by of recycled crank case gases via a PCV system, this goes back into the intake manifold, this can carry oil and other contaminants that can gunk up the valves and intake manifold, this can lower octane ratings of the supplied fuel as well as decrease performance. The can cools and filters the recycled gases separating the oil, water and other contaminates into the can before sending the gas back into the intake manifold. Keeps the engine cleaner.
Sent from my iPhone using Tapatalk