Good Day. I just recently acquired a 98 Impreza Outback Sport for my girl as her commuter. It runs pretty well, idles smoothly, and drives fine. The one thing we have had noticed is that it doesn't have much power uphill. We'll press down on the gas pedal to the floor and it'll shift down (automatic) but doesn't gain very much speed at all. Air filter looks clean and I threw some new plugs in it, haven't changed the wires yet, new tires, has a new timing belt (10,000 ago), and has a total of 158K miles on it. There isn't a check engine light on and I haven't scanned it yet to be sure there aren't any codes. I have read that possibly it could be the knock sensor. Any suggestions would be appreciated. It was owned by an older lady who wasn't hard on it it appears and kept it well maintained. It doesn't seem to get as good of a MPG as I predicted either. I have a '10 Outback which I am pretty sure has a bigger tank by a gallon or two and it definitely gets better mileage. Thanks!