Our 2007 Accord 2.4 liter 5 speed seems to have lost its smoothness. Idle seems smooth at around 800 rpm but it seems to have a delayed throttle response that is noticeable when driving in any gear. Seems that when I let off the throttle and then get back on it there is a delay or dead spot in the car's acceleration that just isn't as smooth as it once was. I have replaced the plugs, cleaned the EGR and ran a bottle of Techron fuel injection cleaner through the gas. No decrease in gas mileage averaging 33 mpg. Car has 170K and was wondering if it is something I can adjust or should I consider replacing coil? I do notice an occasional slight hiccup/miss under load but not constant.