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