Honda 2003 Civic Coupe Owner's Manual page 223

Spark Plugs
NUT
4. Use a wrench to remove the nut
holding the ignition coil. Remove
the ignition coil by pulling it
straight out.
5. Remove the spark plug with
a five-eighths inch (16 mm) spark
plug socket.
222
Maintenance
6. Put the new spark plug into the
socket, then screw it into the hole.
Screw it in by hand so you do not
crossthread it.
7. Torque the spark plug. (If you do
not have a torque wrench, tighten
the spark plug two-thirds of a turn
after it contacts the cylinder head.)
Tightening torque:
13 lbf·ft (18 N·m , 1.8 kgf·m)