Hey man, all I was talking about is that you said "I call B.S. to the "driveline noise" theory," which looked like you were telling me that either I was full of **** or the idea that driveline harmonics can cause this code is full of ****. Since I don't think I'm full of ****, I corrected you.

And also, the reason Mitsubishi bothered putting out a reflash that doesn't fix the problem is because it costs them pennies to try this fix and deny that it's a larger problem, vs. thousands of dollars per customer if they had to tear the engine or drivetrain apart to replace parts where the real defect lies. It's simple cost-cutting. They can **** on us without being punished for it, so they do.

Thanks,
Adam

I have same problem. Started after aftermarket clutch install. Rode on Factory clutch for 3 years with no problem with P0300. 2 days after clutch install, it started in a manner similar to what others have described. It now happens virtually every time I get on the interstate and it is driving me absolutely crazy. I'm definitely with the driveline harmonics theory.

It was discussed here that the flash from the dealerships was essentially about the system not being quite so sensitive to pick up the harmonics issue, addressing a symptom not the true cause.

Well I do believe I have found my culprit. My head gasket is leaking under the intake manifold. It's progressively gotten worse and now my A/F's are all over the place no doubt causing my engine to go lean and misfire. Once I get that problem fixed we shall see what happens.

Drivetrain Harmonics theory supporter here FTW.

The flash is mearly a cover up to change the way the knock sensor pics up the noises. Its a big Mitsu Band-Aid. No biggie i'll just get the tranny rebuilt

Since we are busy telling each other we are full of B.S. I have yet another B.S. theory to toss in here. I notice that if I roll down the rear windows at highway speed that there is this buffeting of the air over the rear of the car that enters the cabin and bothers my ears. Try this and see if your experience isn't the same. This is quite loud in my car.

Could this aerodynamic buffeting, if severe enough, enter the drive train and make its way all the way back to the crank sensor that sets the P0300 code. Or, to put it another way, do the people who have the pointy things at the rear of the roof still experience this code? Could the spoiler really be another Mitsu try at fixing this problem?

Yes, I'm familiar with what you've noticed. It's the most obnoxious I've seen in any car and, because I enjoy driving with the windows down it pisses me off royally.

Is it part of the problem? I sincerely doubt it. The body vibrations are insulated from the engine the same way the body is insulated from the engine vibrations.

Update: Shep (www.sheptrans.com) agrees with me, and I may end up having him rebuild my tranny after all.

See discussion here:

https://www.evolutionm.net/forums/sh...d.php?t=241650

Cheers,
Adam

Never had that problem in my car, but my buddy has an SRT-4, and the plugs were gapped to open, and the boost would blow out the spark. Try tighting up the gap a little bit and see if it helps.

I recently got rid of my misfire (P0300 code) that I've had for a while now when cruising on the hwy...I posted on this thread on page 2 a while back. I previously had the BPR7EIX (Iridium) plugs in there for months. Originally gapped at .026, then lowered gap to .022 and still got the misfire.

But a couple weeks ago I installed the BR8ES plugs gapped at .022 and haven't had the issue since! I even turned up the boost since I had lowered down to 18psi when the misfire was aggrevating me!

I know the Iridiums are supposed to be better, in which I do feel the difference in my idle now...a bit rougher. However it's a small price to pay for getting rid of the P0300 misfire that I kept having for months. I know this helps on some cars, and some it doesn't. Wouldn't hurt to try though.

"spark blowout" ... smaller gap or ingition amplifier are all I know of to fix it.

Those of us who have been battling this P0300 code for some time now have gone way beyond a simple fix such as gapping plugs closer or running an ignition amp. This problem is deeper than that.

I was thinking the same way, however the different plugs and gapping helped me. My next step was an ignition amp which I might still get in the future to be safe.

But yeah, for some it might be deeper...sux!

seems to me lots of people on this forum seriously don’t have a clue what’s wrong with your cars and are just talking rubbish or money from your pockets. For a start spark plugs don’t blow out and transition issues don’t cause a misfire all rubbish comments if your car starts missing at 3500-4000 rpm first thing to check is all your boost pipes for a leak a rip or a clamp popped off once all boost pipes checked check the blow off valve and don’t listen to foolish people I have over 20 Mitsubishi lancer evos ranging from 4-9 if you need help message me and stay away from fools.