Is this true? another p0300 issue....

[spoolin]

I just got my car back from gruppe-s with my new clutch n flywheel. Nothing seems weird, just the usual clutch chatter when coming off the throttle except..... when im cruisin on the freeway around 75 in 5th, a po300 code comes up. Now i've done my fair share of searching on this issue, but i know its not my cam timing or my spark plugs. (I checked them, and this prob never occured before my new clutch install) I have heard rumors from ppl on EVOM that the rough tranny vibration caused from clutch chatter can sometimes cause the knock sensor to go hay-wire and set off a p0300 code. Is this true?

[smack]

i think thats true about the vibration triggering knock or something.

i have this same thing happen at exacly 80mph. and only in 5th. i can't get it to do it in 4th
at the same speed(or at all)

while i'm cruising at a constant speed i can feel the motor start to labor a bit and if i add throttle it feels like i dropped a cylinder.
i have to let off for a second and then throttle again and it goes away. it didn't do this until my track tires started to vibrate a bit from wear.

the weird thing is that it's not pulling timing, it's dropping a cylinder and i'm not sure what could do that except spark.
but since the coil pack run two cylinders each it can't be one of those going out just on one cylinder.
or maybe something that controls fuel but i would think it wouldn't take long to break something if a cylinder went dry.

bryan and you other smart engine management kids, do you guys have any thoughts to add

[spoolin]

Well, at least im not the ONLY ONE with this problem...BUMP for some more info on this issue...

[SpinOne05]

What clutch/flywheel did u have installed? I have a friend that put a lightened flywheel on his WRX and kept getting P0300-multiple cylinder misfire codes.

[spoolin]

I have the stage one Exedy organic street disc with the ACT Prolite flywheel. (Very light, only 10.05lbs.)

[SpinOne05]

How much difference is there on accel w/the light flywheel?

[craziazzmofo66]

i have the excedy hyper single...and when my dad use to drive it, he'd tell me that the check engine would come one for no reason...but i have never seen it on before myself...so its definatly weird...

[jaymzz]

I am having the same problem with the po300 code. The freeze frame on the scanner says 2500 rpms, and 0.00 load? This doesnt make any sence at all. My car only has 7500 miles on it. I do have some mods, but have had them all on for a few months. Any help would be appreciated.

[evo_dadi]

have you tried changing your plugs and gapping them a bit closer?

[jaymzz]

not yet. I will be doing that in the tomorrow.

[z_drifto]

I have been having the same problem and it happened right after i installed the clutch and flywheel. If it is clutch rattle causing the PO300 code does anybody know how to fix it. Concord mitsu was no help. It used to just happen whilecruising in fifth but its starting to do it in more than one gear. If I clear the code its alright for like 2 days of driving, if that.
Ive heard about hooking a code reader up to the car and then just clearing the codes when it happens. But that seems like its just sweeping the problem under the rug.

[earlyapex]

bryan and you other smart engine management kids, do you guys have any thoughts to add

Got some coolness everyone might like. This is Tams car during a misfire like you all are talking about but this is at WOT. Tams car is an 03 but he recently swapped to a 05 ecu. Problem still there, guess it's not the cars ecu making the problem but maybe a sensor feeding the ECU information. Tam said it clears up when he resets the ECU.

Check it out, RPMS break up, AFR goes from 10.5:1 to almost 13:1, timing stays flat, MAF HZ drops, Boost drops, Duty cycle drops.

Guess what other event happens on the evo that does almost the same thing and win a prize. :wink:

http://www.norcalmotorsports.org/users/bryan/mods/EVO/tech/TAM_MISFIRE01.gif

[smack]

just thought i would add this...

mine never did this WOT. it really started on the way home from my last track day but not ever on the track. i just swapped back to my stock tires and
the misfire has gone away totally. in my case it's definitely vibration from the unbalanced tires causing it.

[earlyapex]

just thought i would add this...

mine never did this WOT.

Tam's never did really until now. He also just replaced all his rubber mounts on almost the whole car with much stiffer ones...