New to me Corolla with rough idle is making me crazy trying to figure it out! It idles at a steady RPM, accelerates normally, and starts easily. So far I have cleaned the throttle body, air intake valve, mass air flow sensor, changed the plugs (they looked good), new PCV valve, new air filter (had an oiled K&N) and visually checked all the vacuum hoses. All of that only made it slightly better, Does anyone have any other ideas? Car is 2004 with 110k miles it's making nuts with the idle