just purchased an evo 8 yesterday and it already threw po 300 on the highway in 5th car started to shake and break up until i let off the throttle completely mil light is still on and the vehicle doesnt seem to idle very smoothly has anyone else had this problem and if so what have you done to rectify it thanx!

 

Do a search on the code in the forums, Its been talked about.

 

i have reviewed the forums and i realize it is a common problem but i havent seen anything really that relates to the rough idle or shall i say slight skip at idle

 

I changed my spark plugs and it solved the problem for the most part.

 

w/ my 272 cams installed (rough idle) and Tuned everything..I've never thrown a P0300 EVER...then a few days ago I bought a ETD and was set up on the Stiff'ist setting..ideling for a bit then moving up a little bit & cutting the car off.Turning the car back on and what do ya know....SES light came on.
Pulled code (P0300) cleared it...went home took the ETD off and everything is Perfect.Code has not returned in 4 days.

SHock from the motor (normally noticed around 5th gear off throttle) has been when most people have seen it.
Somehow it triggers the Knock sensor and Throws that code. Creader is the Cure supposedly.

 

etd?????

 

Engine Torque Dampner
"STiffy"
sorry for the abbr.

 

Wow.. I never would have thought the increased vibrations from a ETD or a front motor mount bushing could cause the P0300. This makes sense.. as I threw a P0300 code when I downshifted from 4th to 3rd and I engaged my new exedy twin clutch pretty fast and the motor jolted. I had my powerflex bushing for a few months when I had stock cams and never thew a p0300 code. After I put in a set of 272 cams I get p0300 every time I drive the car. I'm going to swap out my bushing back to stock and see if that fixes it.

 

when i had my 03 i took it to the dealer and got the ecu flashed for the po300 code but it still came on and eventually went away by itself.

 

well..I read that whole thread on the "P0300" and kinda put 2 & 2 together.It really hit me when I thought about the ETD and how much vibration was coming through to my dash.My Defi Dash mounted Gauges and steering wheel were literally about to FLy off my dash.

My car really never had a Shifting issue (1st to 2nd shift) which is what the ETD really helps w/ so I needed a gauge pod so I sold my ETD.

When we installed my cams is when I read that Thread and though "oh lord I'm in for it espcially when I get tuned" but after the tune there was 0 problems and my car dosen't even have the New P0330 flash so that was another thing John @ Jestr told me.

Most people noticed the P0300 in 5th gear but I really think the ETD is what caused mine.

 

I am not sure if the etd would cause this. if mitsu uses crank trigger to determine missfire that is similar to how mb does it and stiff mounts/engine damper shouldnt cause it. bad mounts yes. we have even seen a missfire detected going over tracks, the vibes shook the engine around on its mounts enough for the ecm to see a crank speed variance that triggered a false missfire detection.

 

well I think that the Movement and maybe a noise happens and Its mistaken for Detonation....@least thats what I heard.

 

I have 272s and Powerflex front mount and no problems to date. I've had them for a couple of months now. I'm actually installing the rear soon, hopefully nothing will happen.

 

mine all of a sudden has a P0300 al the time now....I clear it now and it comes right back on the next day.
It use to go away for weeks...now I guss it HATES me.
Had the cams in for 1 1/2 mths before my 1st P030...now all of a sudden it just won't leave.

CREADER anyone? where can I get one?

 

I had this same exact problem in 5th on the highway but never had a rough idle at rest. Got the dealer flash this past Tuesday so we will see if that works. It seem most guys get the CEL all the time but I only got it about every 2-1/2 weeks and 1000 miles or so. So I think I'm going to wait till the end of the month or the middle of July and if no problems, then I will FINALLY be able to put all my parts on and get a tune I hope. P0300 sucks!!!!!!!!