K20Z2 engine

Check the PCV valve (A), hoses (B), and connections for leaks or restrictions.

Fig 1: Identifying PCV Valve And Hoses (K20Z2 Engine)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
At idle, make sure there is a clicking sound from the PCV valve when the hose between the PCV valve and intake manifold is lightly pinched (A) with your fingers or pliers.
If there is no clicking sound, check the PCV valve washer for cracks or damage. If the washer is OK, replace the PCV valve and recheck.

Fig 2: Pinching PCV Valve With Pliers
Courtesy of AMERICAN HONDA MOTOR CO., INC.