hey guys i have a 96Z just turned 130k on it and i got a couple of codes the first one was the egr malfuntion took the egr valve off and that code went away and another one appeared CODE P0300 random misfire. I pulled a coyuple of plugs and then seem to be fine i have about 20k on the plugs and i looked at the wires they seem to be alright alos couldnt get to all the wires but most.. any idea what this could be