EGR delete/faulty front 02.. possible misfire??

[amak87]

I did the EGR delete and removed all the selenoids except for the EGR valve that is connected to the inatke manifold.. I have the vacuum lines disconnected from it... I also performed all ECU mods for the EGR delete.. I am having a misfiring problem, and p0300 cel code. Do I need to get the EGR blockoff plate? Is the EGR valve opening up at full throtttle.Â* I've done everything else I can think of to solve this misfire (compression test, boost leak, new injectors, new lifters, cleaned maf, no exhaust leaks whatsoever, etc..)Â* which only occurs at highboost.. and consistantly during 2500+rpm accels to about 5000rpm.. then the problem pretty much disappears.. or so it seems? I have my knock sensor currently disabled due to phantom knock.. I have also just replaced the spark plugs to stock ngks.

And when I turn off my hks evc, the boost stays at a consistant 11psi.. with no misfires at all. It pulls hard, for 11psi.. I even hit 195+ load. And when I have the hks evc turned on, I can get great gear pulls, as long as I hit 100% tps after 5000rpm... its boosting around 19.5 from 5500 and up.. this problem becomes much worse at 24 psi.

Also, in mitsulogger, my front 02 readings are very inconsistant and bounce around sparatically. My rear 02 stays at a consistant .8xx-.9xx.. (rear 02 fouler used)

Please help. Any suggestions?

[silvrEVOIXn818]

I did the egr delete mod, but left the other solenoids... If you did remove the EGR solenoid, You NEED to have the block off plate!

[amak87]

I did the egr delete mod, but left the other solenoids... If you did remove the EGR solenoid, You NEED to have the block off plate!


So this is the reason for my misfire? Did you have a misfire as well?

[silvrEVOIXn818]

I bought the block off plate, (ebay) and had Reese do the work for me, as I was doing some other stuff. ( mil-spec TB, Int. port match, and ported the hotside ) so I dont know the sypmtoms of driving it, w/ out... But is definitely needed!

check this threa out, if u havent already.
http://forums.evolutionm.net/evo-how-requests-questions-tips/453464-how-egr-removal-viii-ix-charcoal-evap-canister.html

[amak87]

Ya. That's the thread I used for directions.. I'm sure that's my problem. Its only a random misfire. Ill just make one today and report back.

[amak87]

Bump. Please help? Anyone else have any suggestions?

[oldevodude]

front o2 should be bouncing all over the place this is normal. :)
What are your fuel trims? Are they within plus/minus 5% The ECU adjusts trims to try and keep o2 reading steady although it always bounces

[amak87]

front o2 should be bouncing all over the place this is normal. :)
What are your fuel trims? Are they within plus/minus 5% The ECU adjusts trims to try and keep o2 reading steady although it always bounces


Bouncing from .800 to a 0.060 to 0.900 to .500 in ten seconds is normal? My fuel trims are within -1% and -3%... that's fine in my understanding. I'm going to pull the plugs again and regap using a feeler gauge.. and I'm also going to check my buddys evo 8 and see if his front 02 readings react like mine do..

[amak87]

UPDATE: I just removed my egr valve and blocked it off.. I'm still misfiring the same.

[RALLInspired]

front o2 should be bouncing all over the place this is normal. :)
What are your fuel trims? Â*Are they within plus/minus 5% Â*The ECU adjusts trims to try and keep o2 reading steady although it always bounces


Bouncing from .800 to a Â*0.060 to 0.900 to .500 in ten seconds is normal? My fuel trims are within -1% and -3%... that's fine in my understanding. I'm going to pull the plugs again and regap using a feeler gauge.. and I'm also going to check my buddys evo 8 and see if his front 02 readings react like mine do..


the front o2 sensor reading bounce around several times a second. the fuel trims are well within acceptable range. Â*adjust your timing map to compensate for lack of egr and make sure all of the periphery bits involving egr timing are changed as well not just the one line egr disable mod.

[amak87]

front o2 should be bouncing all over the place this is normal. :)
What are your fuel trims? Â*Are they within plus/minus 5% Â*The ECU adjusts trims to try and keep o2 reading steady although it always bounces


Bouncing from .800 to a Â*0.060 to 0.900 to .500 in ten seconds is normal? My fuel trims are within -1% and -3%... that's fine in my understanding. I'm going to pull the plugs again and regap using a feeler gauge.. and I'm also going to check my buddys evo 8 and see if his front 02 readings react like mine do..


the front o2 sensor reading bounce around several times a second. the fuel trims are well within acceptable range. Â*adjust your timing map to compensate for lack of egr and make sure all of the periphery bits involving egr timing are changed as well not just the one line egr disable mod.


Ok. Front 02 is normal.. its not the EGR system. All selenoids are gone. No boost leaks. All nessecary ECU mods done correctly. And this misfire has been happening before any EGR removal.

[amak87]

As far as the egr timing, I have zero'd out any egr timing advanve. However it shouldn't matter since I have the egr and evap disabled in my rom.

[oldevodude]

I was getting the random misfire several times and one time it was plugs and the other time it was injectors New out of the box injectors at that. I had to buy another set of injectors and then proved to vendor that this was the problem. Not sure if it is related but in my case that was the misfire.

Good Luck man as I know these kinda things can drive you crazy

[RALLInspired]

front o2 should be bouncing all over the place this is normal. :)
What are your fuel trims? Â*Are they within plus/minus 5% Â*The ECU adjusts trims to try and keep o2 reading steady although it always bounces


Bouncing from .800 to a Â*0.060 to 0.900 to .500 in ten seconds is normal? My fuel trims are within -1% and -3%... that's fine in my understanding. I'm going to pull the plugs again and regap using a feeler gauge.. and I'm also going to check my buddys evo 8 and see if his front 02 readings react like mine do..


the front o2 sensor reading bounce around several times a second. the fuel trims are well within acceptable range. Â*adjust your timing map to compensate for lack of egr and make sure all of the periphery bits involving egr timing are changed as well not just the one line egr disable mod.


Ok. Front 02 is normal.. its not the EGR system. All selenoids are gone. No boost leaks. All nessecary ECU mods done correctly. And this misfire has been happening before any EGR removal.



As far as the egr timing, I have zero'd out any egr timing advanve. However it shouldn't matter since I have the egr and evap disabled in my rom.


this would have helped in the first post. i agree with oldevodude. sometimes the injectors are faulty or perhaps the coils are not making good contact with the plugs.Â* were this a specific cylinder (i.e. p0304) then we'd at least be able to narrow down the possibilities.Â* do you have a freeze frame of the trouble code?

[Monstergarage]

i bet your problem is gonna be the coils.

[oldevodude]

i bet your problem is gonna be the coils.


How much you wanna bet? :)

He could test coils by swapping their location and see if his 300 series code moves to another cylinder where other coil is... hope this makes sense. could be a lot of different things actually

PS I doubt both coils are bad if this is indeed is the problem.