Noob here. Longtime lurker/first time poster. I've been helped quite a bit by reading these forums and have bookmarked quite a few threads that I refer to from time to time (Thanks!).
So I have a 2005 Legacy 2.5i NA/non-turbo with about 180k miles on it.
A few week ago I noticed that, on acceleration, the car sputtered quite a bit and misfired a few times. Figuring I needed new spark plugs (I did), I replaced them with the help of GEE-OTTOs tutorial (and it only took an hour or so!).
That pretty much solved the problem. It ran perfectly.
For about a week.
Now, when the car is idling in drive, the idle is very rough and the engine will randomly sputter/shake. It's like a hiccup. From what I can tell, this only happens while idling in drive. Occasionally it will sputter just at take-off/initial acceleration but that's only when I start while the engine is 'hiccuping.'
This has been going on for about a week now and the hiccuping has becoming increasingly frequent. I really hope I'm not doing too much damage by driving it like this but I have no other way to get to work (it's only a 3 mile drive so it's not putting a ton of mileage on it).
Any ideas on where to start? I've searched these forums extensively and have a few ideas but just not quite sure.
Thanks in advance!