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Hello everyone,

This is my first time ever posting on a forum so please have mercy on me.

I realize this is a long read so skip to the bottom for a TLDR

Some context: Bought a 2005 Impreza RS Wagon to learn manual on about 9 months ago. I also used this car to learn basic maintenance. (Oil changes, spark plugs, brake jobs, etc.) Everything was going insanely smooth considering the car had about 190k miles and I got it at a steal for $1800. A college student's wet dream. All I had to do for about 7-8 months was change the oil regularly and it was fine. Recently I hit 200k and then all hell broke loose. About a month ago I started the car and it randomly started backfiring out the exhaust. Consistent backfiring that sounded like it was happening with every revolution. I drove off thinking it would be a small issue and made it about 50 feet before it started bucking me around on acceleration and the cel started flashing. I turned it off and checked the oil and the dipstick was dry. I knew the car was burning oil but it had only been a month since the previous oil change and it had never before burned that quickly. I poured oil and got it home. It ran OK for a bit but would still randomly backfire when accelerating. Then randomly the cel came on. The code was P0071 I believe, and autozone told me it was likely the MAF sensor. I bought cleaner and sprayed the MAF sensor and everything was super smooth after that. It drove better than when I got it. The cel went off after about 2 days. Then, about a week ago, I tried starting the car and it sounded horrendous. I accepted that the car was done at that point. It was backfiring, misfiring, and I could hear (what sounded like ) sparks on the driver side. It would also cut power and backfire in neutral. Again the cel came on. I just assumed it was the sensor again. I checked coolant and it was almost empty. Added coolant & cleaned MAF sensor which was enough to get me home. It seemed to run smooth after that but I could still hear sparks.

The problem: After that, I changed the spark plugs and oil and when I first started it after the spark plugs it sounded beautiful. I didn't drive it, just let it run for a bit and assumed changing spark plugs worked. I had also ordered a new MAF sensor at this point. The next day, I started it and again backfiring but not too often just completely randomly and I could smell what seemed like gas. Later that day I started it again to show my buddy and it started perfectly smooth (no backfire) but I could still smell hints of gas. At this point I am lost because I got the new MAF sensor and installed it. I don't smell gas anymore but I do hear sparks sometimes, not very often. When I drive it it runs fine most of the time but sometimes when I accelerate in 2nd or 3rd gear it will randomly cut power and buck the car. Seems to mostly happen between 2-3k rpm. Sometimes it'll just be a small one-time buck and other times it'll buck violently 2 or 3 times until I shift gears. Also, when idling sometimes the rpms seem to be floating around between 500-1.1k rpms and other times it is completely smooth and just stays at around 750rpms. A buddy told me it's probably ignition coils but I am tired of just buying the first thing someone tells me and then having new or similar issues 2 days later. I was hoping to either get a second opinion on the ignition coils or for someone to have had the same experience and fixed it.

I apologize for the long read but I appreciate any help and I will summarize the issue here.

TLDR; Had backfiring issues which cleaning the maf sensor seemed to fix. Similar problems kept returning so I bought a new sensor and changed spark plugs. Seemed to work for about a day and now when I drive it is usually smooth but randomly it'll cut power, backfire from the exhaust, and buck me around when accelerating. Seems to happen only in 2nd and 3rd gear, between 2-3k rpms. Sometimes it's one small power cut/buck and other times it is violent and happens multiple times until I change gears. Also, sometimes idle is super smooth and just stays at ~750 rpms but other times it'll float around between 500-1.1k rpms. Turning off AC seems to mostly help but even with it off it'll still float around sometimes. I was told by a friend that it might be ignition coils but I wanted to get second opinions/other suggestions you guys may have.

Keep in mind this is my first manual car and the first car I've worked on myself so I am not opposed to the issue being completely my fault (maybe I installed the spark plugs poorly for example)

Any help would be greatly appreciated!!
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