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Discussion Starter #1 (Edited)
My car was returned to stock and I might have given the shop wrong boost controller.

Is the one below the OEM one or does it looks like one of many variants of the aftermarket ones?

I am guessing it's the OEM one, and if so, this might explain why I am not hitting what I remember oem target boost levels set for? It's not a dramatic difference, but 1.5 psi, and I am sure that is a slight downgrade in power too? Should I swap it to the OEM one or leave the aftermarket one in on stock or OTS tune?

Are there any other downsides other than lower peak boost? Does it cause it to also spool slower?



Just a moment...
 

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you tune is only good for the controller it is was associated with. Normally there are more changes than just the tune, too. We do not know exactly what you have done - and undone.
 

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Discussion Starter #3 (Edited)
I don't think I was clear...Sorry about that.

I am NOW running NO TUNE. I was tuned (Stage 2). The car was returned to stock by dealership. The car is as if it were new now.

What I am asking is if the pic I posted above is the OEM boost solenoid?

If it is, they forgot to switch that back out. I don't remember the brand I was running before, but it was a pretty simple one (not a 3 port or anything) installed at Snail Performance.

Does running an "Upgraded solenoid" causes any issues on the stock tune other than lower boost?
 

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it looks like a aftermarket one. i found this boost solenoid pic for a OEM boost controller:

https://www.picclickimg.com/d/l400/pict/183539848096_/2006-2014-Subaru-Impreza-WRX-STI-Boost-Control.jpg

and its associated part# 16102AA380 for 2015 sti's. Seems the same part number on my 2012 sti. Visual check on my car confirms that's what it looks like.

running an incorrect tune to your boost controller can result in overboosting. the boost controller controls the amount of boost. You can either get too much boost or not enough boost and incorrectly get them at the wrong moments from my understanding.

If you're going back to stock tune, try to find the stock boost controller... otherwise, it's about $30 from what i can see on ebay.
 

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Discussion Starter #5
if the pic I posted is an aftermarket one, then the correct one was installed when dealer put the car back to stock.

And if that is the case, what on earth is the part I posted used for, b/c it is definitely a Subaru OEM part??

Again, the car is now stock on stock tune... Just not hitting peak boost as I remember. 16psi seems low to me, but anyhow, what is this part?
 

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if the pic I posted is an aftermarket one, then the correct one was installed when dealer put the car back to stock.



And if that is the case, what on earth is the part I posted used for, b/c it is definitely a Subaru OEM part??



Again, the car is now stock on stock tune... Just not hitting peak boost as I remember. 16psi seems low to me, but anyhow, what is this part?


It’s the OEM Subaru EGR valve. You must have done an EGR delete at some point. Most people do it at the same time as their TGV delete.
 

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Discussion Starter #7
well that just makes no sense as it's hard to believe. I though the EGR things was a WRX thing, NOT STi.

Anyhow, never done that mod so the only thing I can think of to what must have happened is that the tuner accidentally gave me this part thinking it was the OEM boost controller (they do look similar).

Too bad I noticed 4 years later.

So what's one the car is aftermarket and running stock tune which is why I am slightly under boosting.

It's only about 1psi difference. I wonder how much I am really giving up by not using the OEM controller.

Is it really worth spending the $30.00?
 

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well that just makes no sense as it's hard to believe. I though the EGR things was a WRX thing, NOT STi.

Anyhow, never done that mod so the only thing I can think of to what must have happened is that the tuner accidentally gave me this part thinking it was the OEM boost controller (they do look similar).

Too bad I noticed 4 years later.

So what's one the car is aftermarket and running stock tune which is why I am slightly under boosting.

It's only about 1psi difference. I wonder how much I am really giving up by not using the OEM controller.

Is it really worth spending the $30.00?

i am looking thru the parts diagrams and can't really find 14774AA500 (the one in your picture) listed other than on older STi's.

as for whatever solenoid is installed, can't you unbolt and check the part number?
 

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well that just makes no sense as it's hard to believe. I though the EGR things was a WRX thing, NOT STi.

Anyhow, never done that mod so the only thing I can think of to what must have happened is that the tuner accidentally gave me this part thinking it was the OEM boost controller (they do look similar).

I thought you had a WRX for some reason. You’re probably right about the tuner just returning the wrong part.
 

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Discussion Starter #10 (Edited)
Update:

So I contacted my tuner from a few years ago, and surprisingly enough, the pic I posted, which is an older Subaru part was used as an "upgraded" solenoid over the stock one in my 15STi.

Probably very few tuners or shops go that route but it's stealthier than an upgraded grimspeed or cobb, but I am sure not as good.

With that said, it means that the one I have installed on the car must be the OEM one if I still had this leftover part.
 
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