The PF 34 receives {HEAD ~ exhaust} from the DOC 32 and filters {TAIL ~ any soot particulates} present in the exhaust 
The PF 34 receives { HEAD ~ exhaust } from the DOC 32 and filters { TAIL ~ any soot particulates } present in the exhaust
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH