I've got a 2003 evo viii, and the service engine light turned on about 34,000 miles. the dealer said it was a random miss-fire code and the're not sure what the problem is. they won't work on it until its back to stock, i have blitz exhaust, hks intake, hks idling sensor, hks bov, and now recently installed turbo timer, and e-01 boost controller. still idles rough and miss-fires. ANY SUGGESTIONS? simply spark plugs, wires, or fuel?

 

Can you check the code?? There is a situation with the Evo having a missfire.....here is a thread on the evolutionm.net website:

http://forums.evolutionm.net/showthread.php?t=88937

Here are the particular symptoms associated with this problem:

It's a malfunction a portion of the Evo owners have been experiencing. It shows it's ugly head most commonly when applying light throttle in 4th or 5th gear at about 3500rpms. The symptoms of this problem include engine stuttering, inability to properly accelerate at light throttle angles and the appearance of the check engine light.

 

no i don't have that accesability to check the code. dealer just said random miss-fire code. it seems to be getting worse though

 

You can take it to any local Autozone and they'll check the code for you. If you don't have an Autozone there is most likely some small auto shop that will check it for near to nothing. The code should read P0300.

 

i can do that and i'll call the dealer now about the reflash program

 

They might need the billing know what you're talking about:

Billing code = 13850113 PCM Reprogramming

 

just called dealer and the reflash is installed in my car. and i do have the hks idling stabilizer but i didn't install it. the symtoms seem correct, but it miss-fires at high rpms and idles rough.

 

I'm not really sure what else it could be; get the code checked.

Did this start happening immediately after your boost controller and turbo timer?

 

with that many modifications, the factory re-flash for a potential misfire is pretty much useless.
people need to realize that modifying a car in such a way will strip the warranty, and generally makes overall drivability stink.

 

check for leaks and is the missfire just fuel cut?