It looks like webgut330i has a grounding kit on his car and he is getting the missfire. I have not had an issue with this at all as of yet and I am at 13,xxx miles. Why are some of the cars getting this and others are not? Of course now that I have said this I am just waiting for it to happen.

 

joey, just you wait!! And my gut is not as big as the intarweb, I swear.

I will check my grounding kit, but in all honesty I'm not sure a bad ground there would affect anything since the factory grounds are all still intact (minus that little dinky one from the head to the firewall).

SC- do you get the studdering problem as well when your CEL is thrown? I've had instances where I cannot feel the misfire, but most of the time it just starts studdering until I release the throttle.

Isn't the car at open-loop continuously after it reaches a certain temperature? What are the criteria for switching between closed/open?

 

hotrod2448, they never did find the problem right? You're probably driving your new car by now.

 

n00dle , hey good input, not the most likely culprit in this situation but you should never leave any stone unturned, regardless here is my post of the official mitsu grounding points for the factory grounding kit https://www.evolutionm.net/forums/sh...ht=hyperground I was dumb and ordered the kit when I purchased the car only to find that the Hyperground kits were going for about 3/4 to 1/2 the price online, back when I was all paranoid about warranty issues with after market parts, basically paid $100 extra for the Evo VII install guide, my mistake is everyone's gain

 

The problem we are having is occurring at very specific throttle inputs, at certain rpm's, in certain conditions. If it was a systems problem such as a bad ground, I'd think the problem would arise in a completely random fashion.

SC~

 

Yes...And it seems to occur more often once the light is already on. But I am VERY sensitive to the conditions that bring on the cel.....so I feel the studder everytime. It doesn't stop studdering until I let off the gas. If I hit the gas lightly again, the studder comes back. If I nail the gas, no studdering.


It was my impression that closed loop vs open loop was partially determined by throttle position. But you can't access the open loop until the car is warmed up properly. Closed loop= optimal emissions....open-loop= optimal performance.

 

Hey guys just for piece of mind check the vac line that goes to your egr, could be that it popped off and has fouled out the plugs, this is just what happened to me though and could be an isolated situation. Put your hand on the side of the throttle body facing the fire wall, move down slowly until you feel a little saucer shaped thing, that's the egr, make sure the line is still on it, if it has blown off it should be just hanging right there, I ended up zip tying my via Al's advice and it has held on with no prob since. Hope that this problem is solve for you guys as quickly and painlessly as possible

 

SC you may be right about the open/closed thing, I am not certain so I can't say. I will check the EGR, I have an appointment wednesday morning so we'll see what's up. My light finally went off after having been on solid the last 2 weeks. There are probably about 100+ p0300's in the ecu's mem right about now.

 

Alright I got the car back today. Short of it is that they found multiple instances of the p0300 code in there, identified it, called Mitsu Tech Line (whatever that is) and they told the service guy that they are "aware of the issue and it is being worked on, however there is no fix at this point."

The long of it is that this is unacceptable to me. I have Mitsu's phone number and will be calling them tonight, and I will also be meeting with the district manager to get some more information. I am about this |-| close to giving them a solid ***** out session, but I'm going to try the nice/funny approach to see if I can get in touch with someone who knows a damn thing about this problem.

More to come... this is #1 of 4 chances they have to fix this before I get a new one on Mitsu's coin.

 

I'm on my 4th visit and no fix. I opened a case file with Mitsu. They will be contacting me soon. My problem is starting to get worse, on my way to work this morning within 15 min on the highway it sarted missing in 5th gear at around 3500 rpm and resume to normal after releasing the gas pedal then occassionally misfire every 10-15 min, but after 1.5 hour on the highway it was missing so bad letting up on the gas pedal didn't even help. I thought it was going to die on the highway. I slowed down and put it in 4th and it seemed to help somewhat. It must have misfired a dozen times in my 1.5 hour drive to work. I took it straight to a Mitsu dealership. Now 2 dealerships are involved more the marrier. Anyway, Im really disappointed in Mitsu and will not get another Mitsu car.

 

Can it be the knock sensor? Anyone with a P0300 misfire replace the knock sensor?

 

that is an interesting idea and I think it could be quite possible, have any of you spoken to Al about this to see what he thinks?

 

The veteran mechanic at the Mitsu dealership in Burlingame Ca. seems to think it's a bad knock sensor and will try to replace it early this week after running it by Tech Line. We'll see if that does it.

 

I have had this code come up on during 4th and 5th gear driving and almost always on the highway. Never has it come on around town untill about 10k miles then it became more frequent, It does studder and has one time made quite a fuel cut feel lurch, the only way out of it is to jam the gas then it seems fine. The Mitsu dealers says it is the SAFCII, But others have had this same problem with or with out the SAFCII's so I just keep bringing it in on my oil changes and having them reset it so they know it is happening. Just in the last 2 months I ousted my cat, so now the CEL is on all of the time, don't really notice when the misfire happens anymore because no CEL notification of it!
My 2$,

 

EvoVIIIGuy, it's definitely not your SAFC as you know, thanks for your input. Hopefully ****su will get around to taking care of this, and soon.