Oddly enough, I have driven for 400 miles now with no CEL...I made no changes to the car. This is the longest I have gone without a cel in the past 10k miles.

SC~

 

SC, it's definitely a conditions/ecu problem. Unless you have it constantly or at a specific point ALL the time, I'd go with that as the cause.

It's frustrating no?!? Mine has been off for 2 days.

 

This 400 mile CEl-less drive occurred right after getting the cel EVERYDAY for 3 weeks....frustrating indeed!

EDIT: As Murphy's law would dictate, the Cel light came back on with my very first ride after posting about its absence....huhu!

 

Murphy's Law struck for me today too.

I took the service manager @ Cortese (Gary) out for a drive for about 40 minutes. Not ONCE did the thing act up, I mean not once. The CEL was there, and he knows the problem is there, he's just not familiar with the symptoms (naturally I'm the first car they've had with this issue).

So he's going to see if he can squeeze any ideas out of the tech line. If the district rep gets involved, he's telling me I'd be wise to put the car back to stock (which means removing the intake, d/v, and turbo timer). Otherwise he's basically going to tell me to take a hike, even though I may have the legal knowledge to tell him it's bull**** and that it's plainly obvious it isn't the mods causing the issue. We'll see if it gets escalated that high.

So I'm back where I started, CEL is on, misfired on my way home today... figures.

 

ok, after the head mechanic at Mitsu (Burlingame Ca.) took my car for a ride on the highway with his laptop diognostic tool, he recorded all the readings while the car was misfireing it turns out that I have a bad 02 sensor causing my car to misfire. They have a new 02 sensor on order and will be installed in the car this wednesday. I hope this fixes it. Mitsu gave me a rental car for 3 days and all diognostics & repairs are under warranty . I'll keep you guys updated.

 

You were getting the same P0300 that we all are, right?

 

any of you guys getting the code used race gas ? just curious.

 

Yes. i'm getting the same P0300 misfire code. It's very vague, lots of things can cause this code to appear. This mechanic is pretty awesome and has been with mitsu since the early 80's. He's had the chance to work on all the Evo models. I'm glad he took time to set up his diagnostic equipment in my car and take it for a 40 min drive with another mechanic. The other mechanics I've seen just took it for a ride and confirmed the misfire but never really trouble shot it, they just kept saying there's no fix for it yet. Anyway, we'll see if the new 02 sensor will cure the problem. Hope it does, fingers crossed.

 

jess that is fantastic news. My service manager was talking about doing a datalogging thing also, I will try to push for that more and see what happens. I'll be speaking with him tomorrow.

Glad you have some seemingly renewed faith in the car/manufacturer too btw!

 

Small update: I put about 4 gallons in my tank yesterday from Quik-Fill (one of these local Northeast gas stations I think). Anyhow, 93oct of course... and what do you know, not a single misfire and the light went off after lunch today. I will be re-filling today all the way and see if that keeps the p0300 demon away.

Up until now I have exclusively used Mobil, Exxon (same as Mobil) and Sunoco gas, always 93+ octane.

I'm not saying there's a definitive link here, but I am conducting a little experiment (albeit without much of a control heh).

 

If it's any help I've used strictly Shell from day one, even Al commented on how little to no detonation my car produced during his street tune, this is in Texas, don't know if there are a lot of Shell's in your part of the world. Happy you are making steps.

 

Definitely making steps. No Shell stations around here, but we have a few others (Texaco, Hess, Quik Fill, etc.). Thanks for the input. Be sure to chime in on my survey thread.

 

Texaco and Shell recently underwent some sort of merger from what I understand, that and my buddies Shell card just all of a sudden began working at Texaco's, coincidence.... hmm..... So try out some Texaco for a week maybe. Shoot me a link to your survey.

 

Here you go, there was a response from someone but it has since disappeared!? Oh well. As you can see it's a terribly popular thread:

https://www.evolutionm.net/forums/sh...threadid=74468

 

this is my experience with the p0300 multiple cylinder misfire code:

I first got it around 3k miles... and have had to reset the code about 5 times. I now have about 13,000 miles.

The difference with my 0300 code is that I don't feel anything different. If my light is off...i get a very very slight stutter (maybe even only in my head) when it comes on. And that's it. The rest of the time the car runs fine even with the light on.

I use crappy Cali 91 octane gas.. and i HAVE noticed a trend with the gas stations here.

I put in unocal 76 gas... and the light stays off and sometimes goes away. ANYTIME i put in Mobile or Cheveron... the light will come on within 100 miles or so.