the vast majority of people running the 8's, actually have no need for the 8's.

especially if you are not running anything crazier than stock turbo.

 

Do yourself a favor and search the P0300 code on here. You'll return thousands threads.

It's likely not a true misfire whatsoever. Mitsubishi's answer to the issue was drivetrain harmonics. 2-3 Rom ID changes to try and combat the issue

Disable the P0300 code routine and never worry about it again.

 

change your plugs often, this is a turbo car and no matter how good the tune it you should change your spark plugs regularly (3-5k miles) on these cars

 

On point

 

Yes, it'll sputter only in 5th gear, usually as im getting on the freeway. I'll go into 5th at about 55mph and accelerate using 0-5psi of boost and the engine will crackle/sputter resulting in not being able to accelerate when it happens. And then from this point on, the car will randomly misfire even when under very little load in 5th gear, sometimes even when I'm just cruising at going like 65mph or something.

 

Is the CEL on when this happens? If so that is the computers response to the code being triggered. If you let off the throttle then back on the sputter will cease correct?

 

I see what you're talking about now, I'll talk to my tuner and see if he can resolve this and maybe I'll get a retune.

 

Yes the CEL is on when that happens. An yes if I let off the throttle, then back on, it won't sputter, but only for a little while

 

Yup clear indication. You can try either of Mitsubishi's Rom updates or save yourself anymore stress, money, or time and disable the P0300 code routine.

Do the latter