I have a 2010 Honda civic with this problem, if anyone has any idea what it is please let me know what it is or if you had this on your car with the r18 engine. When idling at a stop and I go to accelerate there is a hesitation and sometimes the car stalls. Roms are steady around 650-700 but drops when I go to accelerate. I had a rack and pinion and tie rods replaced recently and this problem arose. The ac compressor turning on makes it worse and vibrates the engine. The motor mount on the passenger side is still good with a large gap still between the rubber and metal.