When controller 62 determines that regeneration is complete , controller 62 may adjust valve 22 to reduce the amount of {HEAD ~ exhaust} flowing through {TAIL ~ second conduit} 20 
When controller 62 determines that regeneration is complete , controller 62 may adjust valve 22 to reduce the amount of { HEAD ~ exhaust } flowing through { TAIL ~ second conduit } 20
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH