i have the same problem w my d so it has to be something sensor wise.. when i get on it out of the hole its piss slow then after 3500k its fine and revs fine, its like it didnt have the power to rev up on low rpms.. i have done timing 3 times and just keeps doin it idk what to do.. i even disconnected my cat to see if it was clogged and still the same im puzzled..