{TAIL ~ The exhaust control system} includes {HEAD ~ an exhaust control valve}, and a primary and a secondary exhaust purifying system located downstream of the exhaust control valve 
{ TAIL ~ The exhaust control system } includes { HEAD ~ an exhaust control valve } , and a primary and a secondary exhaust purifying system located downstream of the exhaust control valve
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH