Further, at 204 {TAIL ~ the catalyst temperature} may be maintained between the first temperature threshold T1 and {HEAD ~ a second temperature threshold T2} 
Further , at 204 { TAIL ~ the catalyst temperature } may be maintained between the first temperature threshold T1 and { HEAD ~ a second temperature threshold T2 }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD