Positive Crankcase Ventilation (PCV) System

The PCV valve prevents blow-by gasses from escaping into the atmosphere by venting them into the intake manifold.

K20A2/K20Z1 engines 

Fig 1: Identifying Positive Crankcase Ventilation (PCV) System (K20A2/K20Z1 Engines)

Courtesy of AMERICAN HONDA MOTOR CO., INC.

K20A3 engine 

Fig 2: Identifying Positive Crankcase Ventilation (PCV) System (K20A3 Engine)

Courtesy of AMERICAN HONDA MOTOR CO., INC.