i recently threw a p0300 (random cylinder misfire). my car has the following for mods

-stock turbo, 25 psi
-stock motor
-exhaust,intake,tune, fuel pump
-1 step colder ngk plugs

iv had this setup for about 2 months and started throwing the p0300 over the weekend. just needed some ideas of what to check and posible solutions. i am going to puling out my plugs tomroow to look at em however one idea i had is that i am not getting enough spark due to running so much fuel and boost compared to stock.

sugestions please. i will post more tomorow night after i do the basic checks

thanks in advance

 

what is your rom id?

 

i've had that code every since i got tuned, and i have not been able to find why.
they say some cars are meant to have it, that code can be activated by anything that the ecu saw wrong.
i have rom **15

do you throw the code every time you do a wot pull?
and 25 psi on stock turbo is plenty of boost on stock injectors.
whats your % duty cycle? and 93 octane?

 

as soon as my car was throwing that code someone told me by buying a HKS Dli and i bought one plug it in and never came up again.

 

you need the rom update from the dealer or if you know someone with ecuflash and an updated rom save the updated to you laptop then copy paste your old infor onto the new rom and reflash. I started throwing the code and got the new rom and no more problem

 

I had this problem back when I first got my Evo. It was due to bad harmonics in the transmission which triggered the knock sensor which pulled timing at random points and caused misfires. I brought it to the dealership knowing what the problem was before hand. They put updated components and it didn't go away. They installed an 04 transmission and the problem went away. Haven't seen the code since.

 

I had this all the time till Junior tuned my car...and scaled my MAF correctly...now no codes...

 

im not sure what rom i have. i have the ecuflash, evoscan, and tactrix cable all at my house so how do i figure out what rom i have. shameless does my tuning and iv been on this tune for a while with no problems and good power and no knock.

injector duty is like 100%

doesn't throw the code all the time. only has ever done it once but i hav't driven it much since clearing it

my tranny has been out 4 times so im not sure about 4gsix3T is sayin could be tru