Really annoying Random Misfire

[DSMsOwnYourV8]

I keep throwing a P0300 code - random misfire - when I'm cruising on the intersate. I have replaced the 02 senor, the plugs (Running NGKbpr7's) Ngk wires, the power transistor, and all vacuum hoses off the intake manifold. The cel comes on and the car starts running lean. Once I come to a stop and go again it runs better (while the code is still on) and it will only throw the code in 5th gear. A friend suggested that maybe I try NGKbr9's? Any suggestions? Mods are in my profile.

 

[squeak104]

My car is having the exact same problem. How long ago did you put in the fidanza flywheel? If you search PO300 and look through the threads there are several about the same type of problem. A lot of the people that are having the problem after installing a clutch and flywheel. Good luck fixing it. I haven't saved enough money up yet to replace my clutch and flywheel again to see if it remedies my problem.

 

[oldcarguy85]

how do ## plugs look? Are they fouled at all?

 

[PieEyedPiper]

Assuming you don't have a six bolt, it is likely that your flywheel is the cause. There have a been a few cases of this happening usually right after a clutch job. Other possible culprits include CAS, CPS, Coils, Alternator, and there's a few more. Search around for P0300 Random Multiple Misfire there are a number of very informative threads.
Hope you get it sorted out.

Oh and before you switch your plugs, don't. They're not the cause of your P0300.

 

[96eclipzGsT]

What is the order you have your plug wires installed? You may have a wire crossed.

 

[DSMsOwnYourV8]

This actually happened not long after my Fidanza 5.4 clutch install, but I've had the same fidanza lightweight flywheel for about a year and a half. I really hope it's not the clutch or flywheel causing this because I really don't have the funds at the moment for Dsmlink - which I think has a setting to prevent cel's caused by random misfires?