{HEAD ~ Particulates} in {TAIL ~ the trap} are ignited and burnt off by exhaust gas whose temperature has been raised by the electric heater 
in
{ HEAD ~ Particulates } in { TAIL ~ the trap } are ignited and burnt off by exhaust gas whose temperature has been raised by the electric heater
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 OTH