Alright, I'll start out with some back story on the car. It is a 2002 WRX wagon Automatic transmission that I bought about 4 months ago from a used car dealer. It has a short ram intake and cone filter on it and what looks to be a catless downpipe but I am not sure. I drove it for about 3 months around town, including a 500 mile trip that was all highway driving. About a month ago the car got a lean code that would come and go but the car ran just fine so I checked for vacuum leaks and upon finding none I pretty much ignored it. One day after running lean for a couple weeks it just started to misfire like crazy and would barely run, the car had no power at all. Upon resetting the ECU the car will continue to run good until both long term and short term fuel trims climb almost to 25% and then as soon as the check engine light comes on for a misfire code the car will barely run again, with the engine shaking badly. I've since replaced the spark plugs with standard NGK's, checked every hose and seal for a vacuum leak, cleaned and then replaced the MAF, checked compression and leakdown on all cylinders which came back good, checked and clean all the grounds in the engine compartment, checked the coil packs and connectors and they all seem fine. I would love it if someone could point me in which direction to check next because I am running out of ideas. I can also post pictures of anything on the engine if you want to look at them and I think I have the freeze frame data from the misfire codes here somewhere if I can find it. Any help or suggestions would be appreciated.