I have noticed lately that between those speeds especially at around 65kph (40mph) I get a little bit of a chug, almost like something is holding the engine back. It happens only when I am going at that speed constantly and am kind of coasting/even declerating. It does not happen when I am accelerating past those speeds. I know it isn't coil,plugs,egr related because I tested all of that. Anybody have any ideas. Thanks.