I have a 2001 Lexus gs300 with a p0300 random misfire occasionally it will trigger a different cylinder misfire along with the p0300. The car runs fine except at idle, it has a shake and u feel the misfire but only at idle. I changed the spark plugs and cable. I dnt think it's a coil pack or it would have have me a solid cel code for 2 exact cylinders. If any one can help?
Thanks in advance

 

Take out the coil pack and visual inspect it and then throw some spark plug grease in it.