let me start by saying ive never owned a boxer motor before so i dont know how they are supposed to feel. my teacher is a very experienced tech and he noticed right away that my car sounded weird. he pointed out to me a vibration in the motor as the rpms came down after revving to about 3 grand. and on top of that i started noticing that it didnt drive very smooth. my teacher said that it felt like a piston wasnt hitting correctly like it was skipping or something. the only thing i can think of is maybe the plugs are bad. i have never changed them and my wrx is an 05 with 50,000 miles on it. i dont believe the previous owner has changed them either. the motor is completely stock by the way. i was gonna do a power balance test to see what was goin on and maybe i can figure out which piston is not hitting right. do you guys have any other ideas on what it could be? its not throwing a cel or anything. maybe an injector? i hope its something minor.