I have an appointment to get some work done at AMS on the 31st and I am one of the many that are having the dreaded p0300 code. I changed my plugs one week ago and this is what they look like.



The reason I ask is because they would like the car without the code when I bring it in, which is almost a week. I have an appointment with a local dealer on Tuesday and was wondering how long they would have my car and if they will deny me with an exhaust and intake and boost controler.

This is an 04 Evo with 9,000 miles. I am coming from the N/A world so please excuse my noobness to the Mitsu world. It just pops up at around 70 to 75 mph ONLY when cruising. I cannot STAND this and the CEL that follows shortly after. I am almost starting to regret the purchase due to this.

I have read all about the harmonics and CAS, but in NONE of the threads did there seem to be a "Sure Fix" to this. Please help guys, this is simply ridiculous with such a low mile age car.

 

take out the boost controller, for it will cancel out all warranties

 

just get upgraded plugs like 7 bucks, not a big deal, have ams do it

 

Wow, obviously I know how to change out the damn plugs if I provided that pic.

Will they still provide the flash, with the boost controller? Is'nt the p0300 a TSB with Mitsu?

 

There is a TSB out for random p0300 problems.

Before you go to the dealer, take out that boost controller. They will want to re-flash the ECU to correct the problem. I have had this done to my '03 with little success because I still throw codes every now and then.

The best thing you can do is get a CReader to clear the codes. I got mine as part of my XEDE & smart install ( highly recommended BTW ) from Vishnu tuning. I leave the CReader plugged in and this is the only "fix" that has worked so far.

 

Are they really that brown in real life?

Are you using any fuel additives?

A well tuned cars plugs should be a light tan color.

 

Is that NORMAL looking? Mine never looked "rust" colored.

 

I believe the color is caused by winter gas blends.

 

That is the first time that I have seen plugs look like that.

 

Those definately don't look "normal", they should be a lighter color than that. It may be due to the car running rich, mixed w/ the fact that the winter gas may be leaving a deposit residue.

 

Mind you, these were changed a week ago. So, I am correct in my assumption that this is not the way my plugs should look like after a weeks time?

Being N/A al my life, can I simply unplug the plugs on the Profec 2 and be okay? Or does it need to be removed compltetly? Thanks for the help guys. No fuel additives either.

 

My plugs are the same color. I run Chevron 91 CA gas. No need to worry.

 

those plugs are not burning bad at all. yes could be a little morel lighter in color but they dont seem too rich and definetely not running lean

 

From my experiences in the modding world

Black plug - very rich (10-12 AFR)

white / creamy / light tan - good mixture for cruising. shouldn't be this colour if the car is driven hard (13-14.5ish)

Rusty - not good. very lean and if the car is driven hard ish and the plugs are rusty colour then you are going to break something (AFR of 15 +)

But then again our climate never gets cold enough for the need of a winter fuel. might get to 32 deg F on the odd occasion in winter

Mike

 

Thats VERY lean!!!