VKEVO

iTrader: (12)

Hey guys,

Like the title say I have P0300 code (multiple cylinder misfire), it has been on and off, and for the past 4 days and it still hasn't go off. From what I have read and searched, I see that people just erase the code or leave it alone but I would like to get more info from some you guys who have had it. My spark plugs are new. Does this affect performance or any other things by any chance???

gsrboi80

iTrader: (38)

VIII's are more prone as far as the searching you'll see here.. Mitsu's answer was drivetrain harmonics and 2 rom updates.

Things to troubleshoot:

When does the code trigger (Idle, Cruise, WOT.....)

-Idle-The idle timing may be to advanced

-Cruise-Mivec map may way to advanced, or large gap in between load cells

-WOT-See Above

On the mechanical end plugs, wires, coils can all be a culprit. Usually though mechanical wise you will get an isolated cylinder missfire code as well

mlstrdc

I feel your pain. I was going through the same thing on my Evo VIII. My car would always throw the code when cruising around 65 to 75 mph and start to sputter like my fuel pump was going bad. Several issues were found and repaired:

*Coilpacks were going bad.... Replaced with SparkTech system ( it did not fix the issue but it was definitely work the money)

*Alternator was going bad... Replaced ( The issue remained).

*Cam Positioning Sensor... FTW

I had spent over $1K in trying to resolve my issue just to find out that it was the Cam Sensor.

I agree with the stated information gsrboi80 has provided in the previous post. I just wanted to share my experience in hopes that it may help. Good Luck!

VKEVO

iTrader: (12)

Thanks man for pointing something out, but how did you find it was the cam sensor that was causing the problem?? Because when plugged into the scanning tool, it only says cylinder misfire. Did you find any performance difference after new cam sensor was installed?

geevolution

iTrader: (5)

You can use ECUFlash to get rid of it for good.

VKEVO

iTrader: (12)

I already got rid of it with a regular scanning tool.

DNBishop

iTrader: (3)

I was having the same issue after some mods were installed (so it was narrowed down to that). I read somewhere the JDM cars have it totally disabled, maybe because of the more aggresive tune (as you have). I disabled mine through the peri. bits. It's been fine for 15K ish.
Did it just start? Any new mods? Has it been fine for awhile? If it's been fine for awhile, then just popped up, I would say mechanical.

I could be wrong, just trying to help.

dude

iTrader: (12)

First, search. This has been covered eleventy billion times.

Second, there's no reason anyone should ever get this code with the advent of ecuflash.

Third, you can clear the code with a scantool, but it will come back. Probably in 5th gear at 60-70mph and be accompanied with a shudder until you lift off the throttle.

Fourth, if you don't have a tactrix cable and know how to reflash your ecu and edit your ROM, pay one of the many tuners that can do it. Problem solved.

gkania

iTrader: (6)

Hey there is no reason you should be getting a p0300 code in this day and age. I'll keep the rest to myself.

rburris28

I have just gotten this code twice in the last week, once at part throttle while climbing a big hill on the Blue Ridge Parkway, once at tip in in second gear at about 3000 rpm. No other codes. Car runs fine.

I wouldn't worry since this is so common, but I'm headed to VIR at the end of the month and don't want to lose the CAS or plug wires while on track. I was bedding in pads when the second issue occurred.

Would anyone replace plugs, wires, and the CAS just to be sure, or have at it? I have 67,000 miles on the car, 30,000 on iridium plugs, original wires, mods in my sig. I've never seen this code until now; car has been code-free.

boostless

iTrader: (21)

Sooooo, let me get this straight...you all are telling him to ignore a MISFIRE code??

blacktab420

iTrader: (12)

I had intermittent p0300 codes for about 6 months and one day the code change to P0304.

I bought new plugs and got p0300 again for weeks.

I swapped the 2 coils pack and got p0300 for weeks again.

One day, I got p0304 so I swapped injector 3 and 4 . Guess what ? p0300

But yesterday I finally got it : p0303 !! Just to be sure I swapped injector 3 and 1 and BANG ; got p0301 5 minutes later !

So im in the market for a set of oem injectors !

chrisw

iTrader: (2)

yes but with EcuFlash, you can TURN OFF the checking for the error code completely by flipping a bit in the ECU's ROM.

Evilberry

iTrader: (1)

mine was on for a long time and it made my evo sound like it was cam'd. dave b. turned it off, and never came back

awd_ole

iTrader: (15)

i have that same problem but looks i know where to look now thanx!