What happens is that oil mist gets drawn through the over agressive PCV through the intakes and heads and into the combustion chamber. The oil ignites before the fuel does resulting in pre-ignition/ engine pinging.I'm not entirely sure how a PCV delete would eliminate pinging... or how you got to that condition in the first place.
And you are actually deleting your PCV when you remove it and place breathers in it's place and cap off the upper. It's no longer Positive Crankcase Ventilation because there is no vacuum. It's now NCV- Neutral Crankcase Ventilation.