Hi im new to subarus and this forum so im just gonna spit out my question and hopefully its not dumb.

I just bought my 2000 2.5rs a couple weeks ago and couldnt be happier with it except for the one thing ive seen about it. I have noticed that somtimes when i start my car (after its been sitting for a few hours or more) it will sit and idle at 2k rpms. Usually it will go down reletivly shortly after i start it, but today after work i started it up and it idled high at 2k r's and it didnt go down, i backed up and put it in first and went, but when i shifted into second it kinda of sputtered and was jumpy when pressing the accelerator. Its fine now and it drove without problems other than that the whole way home and rest of the day. Is there something that could be causing this or should i just let my car sit and idle for a half minute or so each time i start it? There are no mods on the car, other than a few cosmetic things the previous owner had thrown on. I would like to begin "upgrading" the car but not till i make sure everything is im proper order and its not going to crap out on me.

 

Does it stink, smoke, or shoot shyte out of the tailpipe?