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Discussion Starter · #1 ·
I purchased a 2016 STi which to my knowledge was bone stock, and recently rolled over to 60k miles and got an oil/filter change. afterwards i bought an AEM cold air intake, cat back exhaust, and cobb accessport for it and installed them all. The car was running perfectly fine before i installed the ap onto it. I put the stage 1+ sf 93 octane tune onto it because i didnt think there would be that much of a difference (maybe run a little rich) because the tune is mean for the Cobb intake, and the car is still running fine, but sometimes when im low in rpm's (1500/2000 right after a shift) it feels like the engine skips and isnt getting any power. is this all because of the tune that i had put on it or is there another problem in the engine that a "standard tune up" might fix?

ps. im monitoring the fine knock learn on my accessport and every now and then it will knock at -1.40, dont know if this is due to the tune or if it was doing it before i put anything on it
 

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I purchased a 2016 STi which to my knowledge was bone stock, and recently rolled over to 60k miles and got an oil/filter change. afterwards i bought an AEM cold air intake, cat back exhaust, and cobb accessport for it and installed them all. The car was running perfectly fine before i installed the ap onto it. I put the stage 1+ sf 93 octane tune onto it because i didnt think there would be that much of a difference (maybe run a little rich) because the tune is mean for the Cobb intake, and the car is still running fine, but sometimes when im low in rpm's (1500/2000 right after a shift) it feels like the engine skips and isnt getting any power. is this all because of the tune that i had put on it or is there another problem in the engine that a "standard tune up" might fix?

ps. im monitoring the fine knock learn on my accessport and every now and then it will knock at -1.40, dont know if this is due to the tune or if it was doing it before i put anything on it
That sounds like a misfire or the car has pulled timing in that range. An intake provides more air, that situation creates the opposite of rich. When you start changing the intake without modifying the mad calibration it's hard telling what result you'll get where. The one thing is certain, for a car known for blowing up engines it's not a risk worth finding out.

It's also worth knowing the factory fuel system is already stretched pretty thin and the intake takes you basically to the limit. I don't think fueling is the issue but it's worth thinking about.
 

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Discussion Starter · #3 ·
well like i said the problem only started after i put the tune on it, also i was told that using the tune meant for the cobb intake with the aem intake would maybe make it run a bit rich, but i was just told that. so should i just go back to stock tune and see if it still persists to try to narrow it down to the tune being the problem?
 

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You should remove the tune and intake until you get the correct tune for the intake you have or the correct intake for the tune you have.
 

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You are playing a very dangerous game -- running modifications that are not properly mapped.

The SF intake has a different diameter housing and a significantly different MAF calibration curve.

Here is the difference for my 2015 STI compared to the OEM airbox


I've never mapped an AEM intake for an EJ motor, but if it's anything like stock, your airflow calibration will be off by as much as a MASSIVE 25%. For a car that's targeting around 10.8:1 at WOT, your car will be actually injecting fuel to produce 8:1 AFR. That's rich enough to cause serious damage to your catalysts and emissions equipment, cylinder washing, and damage to the turbocharger.

Perhaps even worse is that your ECU will be incorrectly calculating load and therefore your timing maps will also be affected.

You need to remove that intake and calibration immediately.
 

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Discussion Starter · #6 ·
thanks zach and jman, will be fixing it asap. i will probably end up buying the cobb intake and selling the aem one, just to avoid future mapping upgrade problems. as you can tell ive no experience in tuning cars, and was just going off of what my buddies were telling me. i knew something wasnt right so i had to seek answers elsewhere, so thanks again
 

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If the aem filter is one of the dry flow filters keep it. I believe Cobb uses oiled filters still and dry flow is far superior.
 
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