the dealer flash doesn't get rid off the misfire issues. all it does is preventing the CELto come on. So instead of 30 misfires count to trigger the CEL, it will now 150 counts. Which Mitsubishi is pretty shady on that. What people don't realize is that the CEL will not come on unless you misfires 30 times or more. just because the CEL doesn't come on that doesn't mean you are misfiring.

 

What are your plugs gapped at?

 

.024, it's not the spark plugs. if it's spark plug it would of misfire at WOT. it doesn't misfire at WOT only crusing on 5th gear 3k-4k rpm

 

OK, well it happened again Saturday on the highway. Cruising in 5th at about 80mph. I'm just going along and all the sudden the car starts sputtering and shaking a bit and the dash lights go dimmer. I left off the gas and then re-apply it and the car feels normal and the SES comes on. Now from what I've read it seems most people don't actually misfire, they just throw a P0300 code but in my case it seems that the thing is actually misfiring. If that is the case, I dont see how a reflash will do anything. And I dont see how the tranny vibration will cause the car to do what it is doing. Do you guys agree that most EVOs dont actually have the problem I have and just throw the code or is what I am experiencing normal with these cars? Again, I am basically stock and untuned (TBE only) and only have 15,500 miles on stock boost so this is really pissing me off. Any advise appreciated....

 

get a CREADER from Vishnu, it works.

 

I was constantly getting the SEL light and po300 code. Gapped the plugs to .24 and still came on more and more frequently. Gapped them even closer to .22, and finally got rid of the codes. No more annoying check engine lights. Want to thank member PVD04 for that suggestion, cause it worked.

 

EXACTLY! I had tried everything for the same thing, and eventually went to an AEM cpu...that was my fix

 

Bingo!!! You are very correct sir. I have an Innovate LM-1 unit on my 05 Evo and I got spikes in the AFR (up to 22+) indicating a blown spark, ie, a misfire. The ECU never picks it up since it is not continuous. But it is there and you I can see it when I download the AFR logs and view them.

The car still runs great, but you will get the blow spark. I have had this happen since before I got the tune with the Xede.

The ignition system on the EVO is crap. It cannot handle the 20.5 psi stock. Mitsu cheaped out on us and gave us the two coils for 4 plugs system rather than go with the COP. The stock system is ok for daily driving, but once you mod your car, add boost and track your car you run into misfires.

I think the best solution is to go with either the Bucshur COP or the Switzer COP, but these are 1K units. I will get one once I have the money. IMO, they are worth it in the long run.

 

Well my car is running stock boost and basically unmodified with just a TBE and I am still misfiring. Not just throwing the code, but actually misfiring. It feels exactly how my car felt before the distributor went out in my old Mirage this winter. Sputtering, no power, and the dash lights dim. It feels like it is about to break down right there for about a second. Also, it happened to me twice in 5th gear cruising, and twice at 2/3 throttle acceleration in 4th gear coming onto the freeway. Seems a bit different scenario than most who post about the P0300. I am going to try the flash and have the dealer look over the ignition system since it is under warranty and some have posted they fixed the problem with the flash, regapping the plugs, new MAF.....I've read them all. So it is worth a shot. Just sucks because I have boxes of toys I wanted to put on soon and get Al to tune my car but now I want to try and resolve this problem as best I can before I void the warranty for good.

 

Do not have AL flash your car if you are getting the p0300. I know someone who did and it fried his ECU. Solve the problem once and for all and then get a dynoflash if you want. Personally, I am opposed to any ECU flash. I kept my ECU as is and used a piggyback. But that is a personal preference.

Here are the steps that I would do regarding the misfire:

1. Change the plugs. Get BPR7ES and gap them to 0.025. If that does not work, try gapping to 0.022.
2. Are you using aftermarket plug wires? If you are take them out and replace them with stock ones. If your stock ones are old, then get new ones.
3. Change the coils. The coils on the EVO are crap. They go out quickly.
4. Replace your crank angle sensor. Some have had luck changing this.
5. If all the above does not work, then take it to the dealer and have them do a flash on the car.

Good luck.

 

By no means are Al and I friends, aquaintences or the like...

With that said, your post is as ridiculous as your fear of ECU reflashes. If I was a moderator, I would say you are maliciously vendor bashing.

 

It is a FACT. Read all about it

http://www.socalevo.net/index.php?op...6&topic=5750.0

I am not bashing any vendor, I am just telling the guy to fix his p0300 BEFORE he gets flashed. Apparently you did not read that part of the post.

 

OK here is your problem, I know because I have the very same problem you have.

the crank angle sensor only has four pick up points, when the tranny gets a little worn it starts to have a weird vibration (most of the time it is in fifth gear) between pick up points the ecu detects vibration and thinks it is misfire so it goes into limp home mode until you release the throttle to reset.

I have tried everything (dealer reflash of ecu, creader,) the creader does the best job of counteracting the misfire.

I am going to send my transmission to shep to have it rebuilt soon but since you are under warranty you should try and have the dealership rebuild it.


when I went to the dealership they told me my exhaust had no backpressure and that was causeing the misfire lol.

good luck and yes I feel your pain.

 

Is one of the CAS pick up points on the tranny? If so, is it possible to make this pick up point less sensitive to vibration so it will not trigger the ECU to think it is a misfire? Is it possible to put a rubber insulator between the pick up point sensor and the tranny? That might help prevent the triggering of a false p0300.

 

My understanding is that the problem is there is only four pickup points for the crank angle sensor vs sixty pickup points on a subaru.

so in between pickup points the cam angle sensor gets no reference point to the crank and the ecu detects knock and bam it trigers the limp mode which we feel as a misfire which is not really a misfire caused by spark being blown out but an electronic safety measure.

the only real way to fix it is to rebuild the tranny with this type of problem.

there are other types of 0300 code problems but the one he is describing is the tranny issue.

btw I had it happend two times today on the freeway, one after the other.

makes you want to park your car in the bad part of town with the keys in the ignition. lol