So after reading the entire thread I ran into the same problem like most of the people here. Last week, during spring break the car started to lose power at low rpm, jerk a bit while driving at low speed, rough idle, but no check engine light. This last weekend the check engine light finally came on. My Legacy is a 2014 2.5i with less than 35k miles. I went to Autozone to get the scan done and they determined it was the coil pack. But to be 100% sure I went to two other places. The other two places said it is throwing a P0304 code but can't determine what the cause would be. But Autozone said it was the coil pack.
Now I tired to see if this is something I could do but space is so limited I have no idea how anyone can do it. Unless the lift the engine up about 1 inch or so it's very difficult. The other thing was I was nervous trying to get the coil pack connector off. Not very easy to do with so much crap in the way. If anyone here have any tips or tricks to do this o cylinder 4 that would be much appreciated. One dealership quoted me 380 to do 1 and the other dealership won't even do anything unless they look at it to determine it's the coil pack.