dreaded p0300 code

[Will2k2p5]

Title says it..

Replaced plugs, wires, coil packs, fuel injection cleaner. I do not have any power issues, it idles high when the engine is cold but sits at about 600 rpms when warmed BUT when idling it does fluctuate maybe 50-100 rpm.

I planned on cleaning my egr valve this weekend but im not sure i that will fix the problem. Manual tranny with 136k miles. Any tips or help is greatly appreciated as I have to pass smog on the 26th.

Thanks!