interesting it goes away with an ECU reset then comes back.. wondering about the EGR system

 

i found this link with infos about faulty equipment on the stock 2003-2006 Mitsubishi EVO 8 & 9 vehicles

http://www.cobbtuning.com/info/?ID=3481


very interesting and well explain even for dummies like me

 

All boost leaks fixed and it's still idleing like poop. And it stalled out on me 3 times yesterday and it's only done the about twice before.

So, I can conclude that a boost leak doesn't nessecerally make the bad idle. But, if you also have this problem you should fix the boost leaks anyway!

My next step is the EGR valve.

 

don't give up buddy..... but do not invest too much money for this problem

hope you find soon!!!

 

id say look into either your throttle position sensor and or idle air control valve, you can test both to make sure there working, and either can cause idle fluctuations... good luck

 

dealing with the same problems right now......im following this post closely. good luck.

 

It seams like all the vacuum lines are all attached. I guess there is one under the car... Im going to check that when i get a chance. Im thinking about doing the egr delete. I also noticed that my vac is about 12psi when it is idling bad and 20psi when it is idling normal. Do you think there is an egr hose that popped off and when the egr sensors tell it to open it doesnt work right becuase it isnt connected right? This makes sence to me becuase it only idles like this when it is warmed up.... Ill keep you guys updated!

 

well most of the vacuum lines are readily accesible, your best bet is to remember where they go remove each, and check each vacuum line for any kind of tears/cuts in them...could be somethin as simple as your boost gauge vacuum line, has a cut in it causing your weird idle.
Good luck

 

same with mine. before when the idle was around 500rpm, the car idles terrible. but then there are times when the idle is at normal, around 900rpm but it would still idle rough. then i noticed my boost gauge and the rough idles only come on when the psi is around what you said.

 

Whats your next step? Is there anything that you tried that didn't fix it?

 

i have almost the same problem with my car to ill be following your thread also hoppefully you get it sorted out..btw is there a way to test the iac valve?

 

Good to hear, i guess this is more a common problem then i thought! You can take the iac off and hook it up to an ohmz meter and test its resistance. But i do know that someone on this thread that had the same problem as us replaced it and the idle was still funky!

 

Try cleaning your trottle body with some throttle body cleaner or intake cleaner..mine used to idle like that too..

 

Let me know if it works!

 

sounds like cams!