Does anyone know why my 03' Evo is misfiring after 4k rpm all the way to redline with some backfiring? I took it to the dealer the other day and they said its because of the ngk plugs (which were brang new from RRE) and that this car was designed to have platinum plugs. The idiot want $200 to change them. Anyone??????

 

Swap back in the original plugs. See if it fixes your problem since it started acting up after you changed them out.

 

Your plugs have gone bad. You can buy the stock ones again for 19.00 each and change them yourself in 15 minutes. Or you can buy the NGK's BPR7ES's or BPR8ES's (colder plug) from a local autopart at a cost of 1.69 ea. and replace them when ever they go bad again for less. The stock plugs are Iridium/Platinum mix. You can go with the Denso brand too. They run around 13.00 each.
Changing the bad plugs will get read of the missfire.
Check the gap. The gap should be between .24 and .27 per manual. You gap them to your application, but stay between those meassurements.

 

You are not interested in helping anyone here. With a statement like the one above all you are doing is wasting time and confusing one of your member friends.
Did your Evo mis-fired when you drove it off the lot?
And what ECU sensors may I ask you are causing the mis-fires, champ?
Care to explain instead of just posting things that don't make sence unless you do!

 

stay with iridiums, i tried platinums, only cause they were the only ones available at the time....biiig mistake...same thing happened to me, sounded like a machine gun

 

Are you modded? Did it misfire even before you changed plugs? How does your plugs look?

Did you recently installed cams/cam gears ? ( Might have jumped a tooth or two )

Thick black smoke under boost out of the tailpipe ? ( overlly rich )


More info would help.

 

BR7ES gapped at .025" and all your woes will be gone guaranteed.

besides copper is a better conductor than iridium.

 

Deleted quote
He is actually not a newbie. He just does not post a lot in here because this forum can get kind of crazy. He is a founding member of our local club dsm (since the 1g days). He knows his stuff.

About your post. I think it may be the plugs. The issue you are reffering to is actually not the sensors being too sensative, its the software being to sensitive in what it interprets from the sensor readings. So you get the random misfire code. When you have this prob on your car, you dont feel it. It is just a pesky light.

I work at mitsu so I know what I am talking about.

If you are getting a misfire just after you changed to new plugs, its most likely your plugs. If you have them gapped wrong you can get a misfire.

Your best bet would be to truy getting stock plugs and installing them yourself, or try different gaps on the ones you have.

 

[QUOTE=dru]He is actually not a newbie. He just does not post a lot in here because this forum can get kind of crazy. He is a founding member of our local club dsm (since the 1g days). He knows his stuff.

About your post. I think it may be the plugs. The issue you are reffering to is actually not the sensors being too sensative, its the software being to sensitive in what it interprets from the sensor readings. So you get the random misfire code. When you have this prob on your car, you dont feel it. It is just a pesky light.
QUOTE]

Thank you very much Dru.
I think there is enough information here now for the owner to make his own deduction and then get his car fixed.
I currently run the plugs I listed and when the car starts to missfire, that is a sign to me the plugs need replacing. Right after I change them, the car runs good until they go bad again. May be there is another reason for the mis-fire. Could be bad fuel, cloged injector, fuel pump, ECU. Who knows. But I know for sure is not the ECU sensors like the "CHAMP" claims. ECU sensors, lol. The ECU has no sensors. Car sensors are wired to the ECU, not built into the ECU.

 

stock are iridiums....NGK IR

 

better thermal/electrical conductivity than iridium, but lower melting point, lower erosion resistance.

 

I had a similar problem as you......it was after 4k rpm while on the boost above 14psi.....


It turned out to be a screwed up fuel pump/filter....not sure how it got screwed up...but something got in the tank that screwed up 2 of them. goodluck

 

He obviously has a miss under load and it sounds like it is consistent. To me I agree 100% with the plug diagnosis.

 

Easy fix since you did not head my warning to calm down.

 

yeh, i make a statement, you delete my post.

why don't we hear what the guy who started this post has to say.

i'm sure he got it fixed by now.

and if he's obviously outraged by the price for the plugs changing, well... either he doesn't know how to change a plug or he's missing some info about his problem.



by the way, mind as well, just banned me from evo m, delete all my posts while you're at it.

since it's not helping anyone.