P0300 99 Pontiac 3.8

Question

Unable to locate source of misfire - wires, plugs, coils, and ICM all replaced - help! :(

Answer 1

P0300 Random misfire

Causes : low fuel pressure, MAF (mass air flow), EGR (exhaust gas recirculation) stuck open.Fuel pressure regulator.

You will have to check fuel pressure the specification are with key on engine off 48-55 psi. Also when the misfire occurs pull the vacuum hose from the fuel pressure regulator and check to see if the fuel regulator diapghran has ruptured