JoshMan88

This is really driving me nuts. I take my jeep to a professional mechanic, spend 160 bucks for him to remove some weird valve cover blow by filter and install an O2 sensor. Jeep runs fine with no CEL for a day.

CEL comes back on with 3 more codes (p0300, p0301, p0302). Take it back to the shop and he finds faulty injector wires and repairs them($114). 4 days later CEL back on with codes (p0300, p0301). I'm taking it back to the shop but seriously what else is there to replace lol.

tjwalker

If you have a P0300 random misfire code, it means the misfire is random and is moving around from cylinder to cylinder. The cause here would likely be something that upsets the engine's air/fuel mixture, such as a major vacuum leak, or unusually low fuel pressure (weak pump or faulty pressure regulator). Look for a "common" root cause here and not something related to a single cylinder.

JoshMan88

You would think with low fuel pressure it would cut in and out while driving... idk. My fuel pump is whining pretty loud maybe that is an issue?