So I drive my car back and forth to school everyday sometimes more than once (its only like 5 miles away). So I drove my car to school three times today and on the final way home the car starts running like crap. It feels like the car is lugging when I try to hold a constant spped. Imagine gassing the car in first gear and then completly letting off the throttle and not touching anything. Youn know how the car feels when you do that, that is what this feels like only not as hard. I have a 2001 ZX3 2.0L with a manx. I really only experience this around 40 mph and in fourth gear. Any ideas?