The sensor is located in an engine component opening, such as a spark plug well, and is engaged with {HEAD ~ first and second walls} that define {TAIL ~ the ends} of the opening 
define
The sensor is located in an engine component opening , such as a spark plug well , and is engaged with { HEAD ~ first and second walls } that define { TAIL ~ the ends } of the opening
OTH 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 HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH