i guess that you have no other faults with the misfire code...
what kind of car?
what miles?
have you had an overheat recently?
how does the car run?...does it seem like it's missing, or does it run smooth?
are you using/losing any coolant?
I ask this because any misfires on cylinders 1/7 /2/8, need to be paid special attention, because these cylinders are directly next to the coolant passages.
It's not uncommon for a leaking head gasket to cause misfires on those cylinders.
and oddly enough...it always seems to be cylinder 8 that suffers this the most :dunno: