{HEAD ~ The reducing agent} is pumped out of a reactant reservoir and to a dosing valve so that after the dosing valve is opened, the reducing agent can be introduced into {TAIL ~ the engines exhaust gas line} in a dosed manner 
{ HEAD ~ The reducing agent } is pumped out of a reactant reservoir and to a dosing valve so that after the dosing valve is opened , the reducing agent can be introduced into { TAIL ~ the engines exhaust gas line } in a dosed manner
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH