For those with the vibration issue:

I finally got a code reader that works (a $40 Creeder did not work as I posted up earlier). I purchased an Actron model CP9125 from Autozone for $79. It's got a nice long cord and big book and everything.
Anyways - P0300. No more, no less.

 

Great idea! I just did it and it took me only 5 mins.

 

I got my car to produce this problem last night while in 4th gear, and somewhat coasting around an off-ramp. First time even in a gear other than 5th.

To me, I'm thinking it's gotta be something in the airflow since you can 'feel' a vibration or flutter via the pedal when it happens. If I don't let off, but instead push down the accelerator for more gas, it'll max out at like 10-12psi and have a god awful loud vibration sound that sounds like something is clogging the airflow. I checked my exhaust and made sure it and the O2 sensor in the midpipe was secure and it was. There's a small leak where the HF cat matches the Midpipe, but nothing major.

Any ideas?

 

You are describing the same thing my car was doing. For me the problem started in 5th gear only, and it eventually spread to 4th, and 3rd.

I'm certain it's the transmission or some vibration in the drivetrain causing it. I believe once it trips the code, the engine goes into limp mode until you lift off the accelerator.

 

Well that's not positive news, but thx. Did you have any modifcations done when this started happening? What have you done to it since if anything to try and rectify??

 

boom it has been documented to occur on several stock cars, no mods required.

I submitted an NHTSA complaint a LONG LONG time ago, I believe it made it up there fwiw. Not that anything came of it.

 

I was getting it both stock and with mods.

At first I thought it was just bad gas, but I tried every brand I could find and no dice. It is quite the annoyance.

Also, when I got the Mitsu reflash it went dormant for about 3 months. But now it's back and as annoying as ever.

 

For those who can't shake it - do you seem to get alot of loud noise at low rpm in 5th???

 

I put my stock air intake and BOV and drove around for a month and got no P0300 error code. Last night, i put my aftermarket intake and Greddy TYpe-S BOV back on and reset my ECU. THis morning, darn P0300 came up again. Intake or BOV have something to do with it? Anyone else have a similar situation?

 

well, i put in a set of 780cc injectors and a Walbro and got a 300 code. Never any issues for 14000 miles then injectore pump and code..... Who the hell knows.....

 

OK I have this same problem with the p300..... kinda annoying... I was wondering if we can either
1. Remove the knock sensor
2. Replace the knock sensor with a different one (from an Evo VII or something)
3. has anyone checked if their plugs to the sensor might have bad connections or be loose... (I just thought of this while typing this) that might explain how seemingly random the time in which the problem starts and how it seems to randomly reappear after just a few miles after it starts for the first time...


This is my first post so please go easy on my crazy ideas... hehe

 

forgot to add to above post...

the loose wire thing might explain the harmonic problem because the harmonics could possibly cause the plug to come lose....

 

Yes, and it continues until you lift off the accelerator.

 

yes to the above question... vibration in 5th.

 

Remove your Knock Sensor? You may as well remove your engine, cuz you will soon after you remove your knock sensor. No Knock Sensor = No knock control, I think of it as an equivalent of driving while blind.


DSM guys used to put washers between the knock sensor and the block, still a bad Idea


BTW the P0300 by the Cam Angle Sensor probably from the noisy cams.