Evo IX - "Service Engine Soon" light blinking under heavy boost
 

Just like the title says. I don't feel any loss in power from the car, just the blinking "Service Engine Soon" light, and the light does not stay stagnate, it only blinks 3 or 4 times under heavy boost and then disapears as soon as i let my foot off the accelerator.

I had a mechanic run a diagnostics for any codes and he said he couldn't find any, so he was telling me it could be my lightweight flywheel causing the computer it to think it's over-revving but that didn't sound right...but i could be wrong

Another variable is that I was tuned on E-85 for a long while and was recently tuned back to 91 for convenience reasons within the last week and a half and have filled up twice on 91 since then, and on my most recent fill-up I added a fuel additive (don't know if that has anything to do with it)

Anyone have any idea what this might be?

It could be that your tuner has programmed it to blink to indicate knock.

^ This. Its a safety feature built into the software your car is running now.

If its constantly happening call your tuner and let him know you need a retune. Tell them whats going on and they should take care of you.

Def knock indicator

usally a blinking check engine light means engine missfire.

whoaaa not good. turn that **** down for now lol

knock indicator like everyone else said...had it put in my tune

I love how mechanics will just say things without having any idea of what's really going on :lol:

Like everyone else said, it's definitely the flash on knock function found in the Tephra ROMs.

fuel has alot to do with knock

:confused:

To the OP:

99% of all stock ECU tuned Evo's run what is called "TephraMod." I would be willing to bet money this is what your car is flashed with. TephraMod has an option where it will blink the check engine light when knock is detected, and pull timing to save the motor. If your tuner has the timing too aggressive for a 91 octane tune, then there would certainly be knock at high load and the light would blink.

Take your car back to your tuner and tell them you need it fixed. Or there are also a host of tuners here on the forums who can do email tunes if you have the correct cable.

-Acree

Yea, a blinking check engine light is for a misfire, unless it's obviously been changed to indicate knock by a tuner. Either way, it's not a good thing.

I will also agree it's prolly knock especially if there are no codes in your ecu when you plug into it. Are you running dual maps with a switch or are you flip flopping manually with ecu flash?

Lol at your mechanic Please find a new one

Just an update, I talked to the guy who originally tuned the car (not the idiot mechanic) and he informed me that it was a feature he put in the ROM to let me know when it sees knock. He said there is slow flash knock (3 counts or less) and the fast flash (5 counts and up). He said it's probably due to the result of heat soak because of the temps and humidity we have been having in Arizona lately and of course 91 octane pump gas.

He said that if I am doing the same pull and the knock is consistant, then just swing by and he would fix it until winter rolled around.

While this sounds legit, I'd probably go and have the tune tweaked to be a tad less aggressive just in case? You'd be sacrificing a tad of horsepower to prevent grenading your motor?

Just my opinion...