So, I bought a used (subaru certified) '06 WRX in the recent past with 15k miles on it. Everytime I turn on the engine (unless the engine is already hot from only have been off a few mins) it idles at around 1,500 rpms. I cant remember this happening with other cars ive had. It will idle there for a few mins and slooowly come down. But I usually dont wait long enough for it to come down before i start driving, unless its cold outside. Once i start driving after a few mins, it starts to normally idle around 600 or so. I havent experienced any problems yet, i just didnt know if this was very abnormal or not? Any thoughts or explanations would be helpful.