2001 Toyota Camry Rough Idle Problem

A Rough Idle When I Start It Up Everyday

Dear Scotty,

I have a 2001 Toyota Camry LE with a rough idle problem. It only happen about once everyday when I start it up in the morning, but after that it start up fine for the rest of the day. The car makes a loud noise with an RPM at around 1700 to 1900 when the problem occurs. I have changed the spark plugs, ignition wires, valve cover gasket (because it was leaking a bit of oil), and the PCV valve plus its grommet since the problem occurred, but my remedy did not completely solve the rough idle. Would you offer me some suggestions? 
Thank you very much Scotty.