P0300 is nothing more than the knock sensor being veeeery sensitve on 03 evos due to trans vibrations. I have goten before plenty of time and the funny thing is that i do not notice a misfire or loss in power. Some people get a reflash at the dealership for $150 (i think) and some just lower the sensitivity of the sensor through ecuflash when they tune the car.

 

do you have transmission vibrations in 5th gear?

 

It is my understanding that it is not the knock sensor but the crank sensor that is involved. When the triggering of the crank sensor has certain irregularities the p0300 code it set.

 

its neither sensors its either rom upgrade need new id or for my car its a tsb needing to change 5th gear input shaft seal a $1.73 part of which mitsu is quoting me as today mar 5 2011 $1721.34 plus tax. feel like i want to eat a bullet.

 

F that. I'd just send the tranny off and get it rebuilt/upgraded for right around $1k or a little less. Also, updating the ecu rom (as stated earlier) and getting a tune always helps. My 03 used to always do that. Now it's been 4wstuned: quoth the raven, nevermore.

 

I too had that code but it finally spit the misfire code for cylinder 2 and it ended up being a bad injector.

 

Had the same problem. had all of these problems at once
1. Bad spark plugs (cause by the next)
2. Broken Coil Boot (metal piece)
3. Bad/Clogged Injectors

All of the following plus RANDOMLY my CEL light would come on


had a tuner shop fix all of it