Check your spark plugs, if that's not the problem, check the IACV. IACV is your idle air controll valve, and is what lets air through during idle/start up. Sometimes they can get stuck or moved. Basically just twist it back to its original place and your idle should settle, I had the same problem with my EK D16Y8. EricTheCarGuy has a tutorial on how to fix it; http://www.youtube.com/watch?v=L788jKEVblY Hope this helped. -Alex.