My mods: Buschur Stage 4 + methanol + exhaust cut-out
Plugs: NGK Copper (BR8ES) gapped at .022

On a daily basis, at least once a day, while my car is idle'n, it will randomly throw a CEL for P0300. It will happen somtimes 5 seconds after starting the car, sometimes hours afterwards while at a stoplight... very random. When it happens, the rpms will dip low for a second like it is going to stall, then recover back to idle. I know the typical P300 code occurs while driving (usually in 5th gear), but that never happens for me. Driving the car is perfectly fine... just randomly misfiring at idle. I've tried all different gaps for my plugs... .032, .026, and .022 now. I've tried BPR8ES's and BR8ES's. This happens with either plugs and even with brand new plugs. Can anyone provide any possible solutions to fix this matter?

 

Magnecor 8.5mm plugwires and a decent grounding wires (homemade 8ga wires will do).

 

Any particular reason why you are rolling copper plugs?

 

Copper plugs are fine but they won't last long enough. You have to change them out with the oil's interval.
But if you are still boosting 30 PSI everyday I would suggest getting Idirium back in there.

 

i had the p0300 code pop on very randomly like yours does. sometime right after i start my car and sometime while in 5th, and sometimes at a stoplight.
I never got it too often. Maybe once a month or so.

My car was tuned on a dyno by (rather not say). Thats when i started throwing the P0300.
After i tried everything to fix the issue i finally tried to get re-tuned by another tuner. That was 5 months ago.
Having thrown a code since. I also have not changed anything on my car since.

PM me if you want to know who did either tuning.

 

By rolling, do you mean gapping them extra tight? If so, I was told to gap my plugs tighter as a possible resolution to my misfiring at idle problem.

This code popped up even with a fresh new set of plugs gapped at .026 and .022, before I even boosted.

 

I have also noticed a big difference in how often I seep P300 codes depending on which set of maps I'm running in my piggy-back. The rule of thumb in my car seems to be that if I'm running esentially stock timing, I see very few P300 lights. If I'm running a map with retarded timing I see them far more frequently.

I can't say anything about advanced timing - while I experimented with it slightly on a dyno, I've never run more timing advance than the stock ECU provides on the street.

 

I Get The Same Thing At Idle Car Has No Problems The Light Will Shut Itself Off And Then Come On A Few Days Later Sux Cause I Need An Inspection Sticker In Two Weeks..but I Dont Worry About The Light Anymore Cause Thes No Fix

 

And what makes you think that this will resolve the issue??

 

Oh no sorry, I meant why are you using copper plugs.

 

I was recommended to use 1-step colder copper plugs by virtually every Evo tuner.

 

*bump*

 

--;

 

I kept throwing 0300 code after my custom dynoflash....faster than i can undo my -ve battery terminal! I read on evom that there is a TSP fix for the 0300 issue. Took it to the dealer and asked for the 0300 reflash, the 0300 issue is fix, havent appear for ~1200miles.....and my custom flash is gone...

 

Were you throwing the codes while driving like most other ppl are... or at idle like I am? I'm wondering if my issue is different from most other people's issues...