I have a 2007 G35 Sedan. It has 166,xxx KM which is equal to a little over 100k Miles. At cold start everything about the car is perfect. It starts fine, idles fine, etc. Once warm if cruising around 40-55 miles per hour you will feel/hear an occasional hesitation like the car is doing a quick cough. Also, if car is parked for a while(not long enough to get cold) the engine takes longer than normal to start almost as if it's choking. It doesn't do that every time but more times than not. Things that have been changed or tried in troubleshooting. Another thing when the car experiences this "cough" if idling when revving the engine it will have a slight drop"cough" at around 2kRPM. Any help or suggestions will be greatly appreciated.

New CPS
New Fuel Pump
Clean MAF Sensors
(I will say when all of this was done it was definitely better for a while)
New Spark plugs
Car has aftermarket in take and the filters are fairly clean..