need sumones help!!!!!!!!!!

i have a 2000 silverado wit a 4.8 v8... i had it n a shop for five months wen i got it back it was missing real bad so i change da plugs, wires, and even da coils...this did not help so i pulled da code...it was p0300 muiltiple miss firing on cylinders....cant figure it out took it to 3 different shops and dey all told me da injector were dirty to jus run 93 octane...this was a month a go its still doing it....CAN SUMONE HELP!!!

did you gap the plugs

jk man. i googled the code and it had these possible causes:-Faulty spark plugs or wires-Faulty coil (pack)-Faulty oxygen sensor(s)-Faulty fuel injector(s)-Burned exhaust valve-Faulty catalytic converter(s)-Stuck/blocked EGR valve / passages-Faulty camshaft position sensor-Defective computer

THE PLUGS CAME PRE-GAPPED BUT DOUBLE CHECKED TO MAKE SURE DEY WERE RITE...USING AC DELCO IRADUIMS

da da da da da dey

i just posted a thread with the same problem. i changed everything you did, plus, cleaned the intake, changed the fuel filter and a few other things. i disconnected the battery to reset the computer and it seems to be doin ok now. still a slight miss when i stab out though but a huge improvement...im hoping another code will pop up insread of that random moss fire. i have the 4.3...

check O2 sensors when i had my truck this code came up for mine and both bank O2 sensors were bad changed them and nvr had a problem again.  could be one or both

start the truck up and pull the vacuum hose off of the fuel pressure regulator, see if you can see any fuel coming out of the vac port of the regulator, this is a common problem on the older ls motors. the regulator diaphragm gets a tear in it and bleeds raw unmetered fuel through the vac port causing p0300 codes. if so its as easy as changing the pressure regulator. you might have to stick your finger on the port of the regulator and see if you get any wetness.

one more thing, these trucks are real bad about the plastic intake manifold warping and causing vacuum leaks which also set p0300 codes. but its kind of an expensive part to just be throwing one on it.

my truck did the same thing and had the same coil on my 4.3 it was  the distributor . also is there a cowl hood ive heard theres a problem with water leakin down onto the cap on the chevy trucks