I have a 2004 Acura TL automatic. The past couple of days my TL has been having idle issues. When starting from a cold engine the car is fine, as soon as it warms up the issue begins. when I am actually driving and giving it throttle the car runs fine. It is when I stop at a red light or for more than a second the car begins to drop rpm, as it drops the car vibrates through the steering wheel and floorboards and the engine corrects the drop rpms and goes back to normal. It kinda feels like the engine is misfiring in idle. Now if I put the car in neutral the vibration is reduced a fair amount, however, you can still see the RPMs drop and rise. This began to happen after a heavy rainstorm. I do not know if that could be a factor. Also, I did an oil change a week prior to this issue surfacing. This is the first oil change I did to the car since purchasing 1 month ago. I am not sure if conventional oil was in it put I used full synthetic when changing. I am reading a lot of stuff it can be, everything from EGR valve, to spark plugs, vacuum leaks, to even motor mounts. Was hoping someone can maybe point me in the right direction in tackling this idle issue.