And to think the entire time, a simple fix was nothing but a $20 CReader from Ebay.

 

Just one more very good reason to "look forward to" the beefy drivetrain I plan to build. A bombproof tranny and xfer case is good. Eliminating P0300 at the same time is great.

 

I now have around 600 miles on my car without throwing a code. So far so good. I will update IF I throw a code.

 

I tried to find the answer to my question in this thread, but to no avail. I have a FMIC and intake, thats it. At WOT I would get a bog/stutter around 5k rpms. Today as I was merging onto the highway, I threw a CEL at about 3500 rpms, would this be something that this "reflash" would fix or is it a tuning issue due to the FMIC and intake.

 

doesnt sound like the P0300 code. the P0300 code is a false misfire code that doesnt really cause any diveablity issues with the car. i have had the ****ing code going on and off for the past month and still havnt found a fix. and yes i have tried the Creader and nope! did work at all let alone clear the code.

 

a lot of people in the thread are sayings its one of 2 things.

1. drivetrain noise
2. coils/plug wires
3. drive without the plug cover on

well i have a ACT HDSS with a lightened flywheel so im not so sure its this

the coils are stock as are the wires. i just changed from BR7ES gaped at .026" to BR8ES gaped to .022". im going to see if the plugs make a difference and go back to the BR7ES.

as for the plug cover, i have a AMS one thats metal. so i will try and drive without it off and see if it helps.

 

Thanks for the response ^^.

 

Seems like the dreaded p0300 code is still with no solution. I recently went back to stock exhaust and got the p0300 code today. I was thinking why don't we just put the CEL fix bolt on the stock cat? I still have the bolt from when I had my test-pipe and I never threw a light. Wouldn't that solve the problem?

 

No, the P0300 code is for random knock events, not cat inefficiency.

 

but then why would I all of a sudden throw a CEL when going back to stock exhaust? Not saying that I don't agree with you because that makes perfect sense. I was CEL free until now.

 

Well did you verify for sure that the CEL you are throwing now after changing the exhaust is definitely P0300?

My question is: for you CA owners: I hear they don't even like to pass you for emissions with a CEL, especially like P0300. How are you dealing with this? Do they actually read your codes? We don't have emissions testing where I live at all, so I have never dealt with it.

On another note, from what I have read on this thread, hasn't a tranny rebuild had the highest success rate of anything with fixing P0300? Not that everyone should go and shell out for a rebuild on a good tranny to get rid of it, but those of us who plan on upgrading to Shep/TRE rebuilds can hope to have at least a good chance at eliminating it right?

 

To throw another mystery solution in the P0300 soup.....

Never got the P0300 till sometime after I installed cams and cam gears. I say sometime because I'm not sure when it started as I also had a testpipe with no cel fix so I just stopped pulling codes thinking it was the cat inefficiency code.

I've also had the engine cover off for quite some time, no affect on the p0300. Tried everything to cure the P0300, changed the tune (added timing, removed timing) tried bpr7's, bpr8's, br8's, new plug wires. It was chronic, clear it, drive for 5 minutes, pending p0300 would be set again.

Added water injection and a haltech interceptor, after the first time I tuned the haltech and WAI the p0300's went away and have not come back since.

Used to get them at Idle and light cruise. When I tuned the haltech, I added 1/2 degree of timing everywhere then ramped it up in the load areas.

Previous EcuFlash tuning I went through adding and removing several degrees of timing in the idle and light load areas to no avail.

Exeed's were known to induce the p0300's if you added any timing at all.

I think in my case the real issue is with the crank sensor and by having the haltech modify the signal just slightly is enough to stop the p0300 codes.

 

I guess i am one of the lucky one's I have never had the P0300 code. My neighbor gets it sometimes on his 03 though. We are going to replace the plugs, check the wire and coils to try and find why. I have all the bolt ons and my neighbor has an intake and a catback with nology wires. I am betting his problem is in the wires.

 

Yea it's not for certain that my code is a p0300 but I can almost put money on it that it is. I already had this feeling that before I took off my exhaust system that I may re-encounter this problem. I mean I was running with my full exhaust setup for almost three years without throwing any codes up whatsoever, except for when I put on the test-pipe, but I resolved that with the CEL fix bolt. Then two days into driving with stock exhaust and this happens. Damn you cursed 2003 Evo!

 

I have 107k miles on my car. Just did the clutch at 105k. I have literally up until the day after the clutch install thrown the p0300 code once in all of my miles. I replaced the clutch with the exact same one as I did before with the only difference being that I used a full weight stock flywheel this time around instead of my previous lightened stocker. New transmission is simply not an option right now and I have no chance in hell to have anything warrantied. I am going to attempt to disconnect the drive shaft from it's mid point rotate it, and then reconnect it. Reason being is that I did not, for some unknown reason to me, mark the position of the shaft at that point when removing it and believe that it being out of orientation may be causing it to be out of balance, causing the resonance.

Opinions on my theory?

Josh