The system 1, wherein {HEAD ~ a ratio} of {TAIL ~ plugged area} to the total cell area of the flow through honeycomb substrate is less than 45% 
The system 1 , wherein { HEAD ~ a ratio } of { TAIL ~ plugged area } to the total cell area of the flow through honeycomb substrate is less than 45 %
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH