Problem with a 1996 Subaru Outback

engines
lights
cylinder
misfire
#1

Ok. I know this is supposed to be a great car, BUT I have had it for a year and had a continuous problem. The check engine light has been on a lot and lately the car has begun to sputter and die at stop signs. This is not safe. Last summer I had a full tune-up, replaced the alternator and replaced a bad spark plug this past week. When put on “the machine” the check engine light shows that there is a misfire on cylinder #4 (why the bad spark plug was replaced). Once again it is having the same symptoms and I don’t know what else it could be. Any suggestions? Thank you in advance!