dirty fuel filter, dirty air filter, clogged injectors, bad o2 sensor, dragging brake, poor alignment, low compression...i think that about covers it?

you may want to change your tranny fluid as well, get a valve adjustment, replace your air/fuel filter, use a k&n for the air filter, and run some injector cleaner through the car. while you're running injector cleaner, RAIL ON IT every day, to clean things out.