when my idle on my hatch was messed up like that it was throttle body make sure ur gasket is good. if you take the intake off start ur car there should be a hole in the inside stick your finger over the hole it might hurt a lil because it sucks really hard, but when u do that ur car should go back to a normal idle if it doe then its ur tb gasket if you need one i have 2 because i just fixed this on my car last week. hope that helps.