Toyota Repair: 99 corolla hesitation/check engine light on, engine misfire, coil pack

Question
99 Corolla 80k miles.  First owner was my grandfather who was not hard on car at all. Not sure about routine maintenance, we have car bc grandfather is hospitalized with alzheimers.  Car has had check engine light on for about a month,  which coincided with the car beginning to hesitate on acceleration.  The hesitation progressively got worse, almost seemed ready to stall at times. Still ran rough even when not accelerating.  Slightly rough at idle.  Stopped driving it, got taxes back so now can take in for service.  Checked the gas cap to see if that had anything to do with engine light, did not help.  Car is used in commuting, lots of stop and go traffic.  Checked fluids, they are normal.  Otherwise car has driven great, we have had it since September last year.  I love it and hope the repairs are not more than the value of the car!  I am disappointed because this car has low mileage and I know it was babied.  Also ITS A TOYOTA!!!.  My last Toyota had 200k miles ran wonderfully before I finally gave it away.  Please advise.

Answer
It's probably just an engine misfire condition which is common, this may be due to a bad spark plug or a bad ignition coil pack, each cylinder has it's own coil/igniter but to be sure I would recommend connecting a diagnostic scantool to determine the trouble codes that are stored in the computer, doing this will isolate which cylinder has the misfire.