Random Multiple Cylinder Missfire

i scanned my car because of an SES light and a PO300 came up ( random multiple cylinder missfire) i dont know which cylinders are missfiring. a mechanic told me that my plug wires might be crappin out so i bought new pluf wires ( magnecor 8.5 mm wires). next day i get the light again. the thing is that when i scan it i get 2 codes and they are BOTH PO300. either my coil packs are goin bad or i dont know whats goin on. my mechanic said it might be my crank sensor or my cam sensor. what could be causin this problem?? its driving me nuts. thanks in advance for any help guys. By the way the car is a 99 z28 M6 with 78000 on the clock. mods: LTs, manley pushrods, rocker arms, valesprings, slp cold air kit w/lid, stage 3 spec clutch, and im runnin an open y pipe with 02 sims and a skip shift eliminator. some of this stuff is probably not any help but im just lettin yall know exactly what i got here. thanks

Yep, I'm thinkin the same thing. Cam sensor most likely. It tells the comp when #1 is at TDC. I've seen a couple cars with bad misfires and intermitent stalling and cutting out due to the Cam sensor. If the resistance in the sensor changes the signal to the comp changes. What kind of plugs are you running? I had platnums in the Cavie and it ran like crap after 200miles.-backfiring, severly delayed timing.

Cheep and somewhat easy first, check your plugs.

im runnin autolite plugs.......and sometimes my rpms will drop real bad and cause the car to stall. how much does a cam sensor cost?

Here is a more descriptive answer to the code. It has a diagnostic table to try and help you track down the problem.
http://www.gearchatter.com/viewtopic8880.php