Hey guys im new to the forum and i just have a few questions.. I drive a 2000 eclipse gs with around 129000 miles on it, and recently ive noticed that my rpm would go up and then down when i was in neutral. I assumed that it was something to do with the idle control so i hooked it up to a computer at school and i got this message PO505 idle control system, so ya i was right. Now i wanna figure out how to fix it, but i have no clue and im not quite the mechanic so if anyone can tell me what is wrong with it and what i should do to fix it it would be greatly appreciated, oh and price figures will be VERY helpful as well. Thanks guys
-Jmc193