Just had the same problem...after the car would warm up it would fluctuate from 1000 to 2000 rpm. I took it to a local mechanic..roipped me off...didn't fix it...gave up took it to the Honda dealer and it was nothing but that they cleaned the throttle body and the IAC valve. There is a little wire mesh filter inthere that gets clogged wiwth carbon and confuses the IACvalve...they just cleaned it, didn't replace it. It cost me $266. at the Honda place. You might get it done cheaperm but Honda knows what they are doing..so I actually spent more money before I took it there..I should have took it in the first place. 3 different mechanics told me 3 different things and none of them fixed the problem.....GIVE UP take it to the honda place get the throttle body cleaned!!!!