Hi everyone. I have a 2009 Impreza, 5-door, 4 speed automatic. Ever since I got the car last summer, I've had a problem with the engine rattling while accelerating, especially uphill. If I am getting onto the freeway, for example, the car will shift into 3rd and rattle for a bit, then shift into 4th (too soon in my opinion) with a lot of rattle and no power. The rattle is similar to the sound a car makes when you shift in too high of a gear for the speed you're going in a manual transmission car. If I give the car extra gas to make it downshift, I have more power and there is less rattling, but still some. So I think it's the transmission. The car definitely does not stay in 3rd as long as it should and in general doesn't know when to shift at the right speeds. Anyone know how I can fix this? thanks.