A misfire detector generates a misfire detection signal indicative of occurrence of {TAIL ~ misfiring} in {HEAD ~ the at least one engine cylinder} on the basis of a value of the ion current 
A misfire detector generates a misfire detection signal indicative of occurrence of { TAIL ~ misfiring } in { HEAD ~ the at least one engine cylinder } on the basis of a value of the ion current
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH