Sounds like you either have a manual boost controller, or a wastegate that won't open. You sure its all stock, no exhaust changes? Check to see your wastegate even opens or the lever's been adjusted. No "stock" car will just decide to overboost without a mechanical failure / modification of some kind...I'm leaning on that when it was put back to stock from the previous owner something was not reassembled right..

 

+1.Does the car have a boost gauge?

 

yeah its completely stock no mods at all....it did have one previous owner so i think that it could be a possibility that the guy who had it before me did mess around with the engine and when he put everything back he messed it up...is the actuator on the wastegate supposed to be movable by hand?? i tried moving it but it wont budge at all....theres no exhaust upgrades either on the car its all bone stock the only mod i have done to it are front lowering springs....and yes i do have a boost guage it came stock with the car and when i am boosting all the way the boost guage does max out at .15 MPa which is 21.75 PSI....that doesnt sound right??? i just noticed that now i never really checked that out before is the boost supposed to be that high? Isn't the stock boost supposed to be only 12 PSI? Im confused

 

Yep, you are way over! Boost should not exceed the 14 psi range during your average "run through the gears". For whatever reason your wastegate is not opening to control the boost. As for the wastegate being able to open by moving the linkage, that won't happen. You have to disconnect the lever from the arm/linkage on the side of the turbo. Be careful that you put it back at the same orientation. You may have to remove the heatsheild. Take a picture of the engine bay. The boost soleniod is on the left-hand side, near the strut tower. Lets see if its stock, as well as the vaccum lines being stock. If you can't move the wastegate (after disconnecting the linkage), then that turbo will have to come off, somethings wrong internally.

Another option is that you have an after market exhaust system and theres too much free-flowing air and you're overboosting because the wastegate/soleniod can't open quick enough. Are you familiar with what a wrx stock exhaust looks like? It should have 2 cats from the turbo back, and a precat in the pipe comming up to meet the turbo from the manifold. Are you 100% sure that it is? There'll be some stamping of the Subau logo and such if it is...if there's no heat sheild over the turbo, that'll be your first indication that your turbo/exhaust was messed with.

It has to be one of those options. Either way, I'd hate to say it, but it looks like your car was modded, and an attempt was made to put it to stock. You're not getting the full story, IMO.

Take that pic, post it, and we can take it from there.

 

Heres the pics you wanted...i hope they can help out

 

so this is how it looks when im in third gear....the boost was at .15 but by the time i took the pic i wanted to switch....thats in second gear...shortly after my cel went on...

 

Well, first thing I see is the heatshields that cover the turbo are missing, and the bolts look like they've been off before. That means at some time you had an aftermarket exhaust. I can't see the uppipe (the one that connects to the bottom of the turbo to the manifold) It should be thick and shielded like your downpipe (the exhaust pipe off the back of the turbo).

Another thing is the linkage that operates your turbo. The orientation looks wrong. Here's one at the correct orientation and spacing:

Compare it to yours, see what you get.
Also, to check to see that the wastegate will open try one of 2 ways:
1. disconnect the lever to the linkage on the turbo by the retaining ring there. then try to move the wastegate linkage.
2. Remove the vaccum lines on the diaphram (the bronze oval disk that the level comes off of). This should allow it to move freely, hence you should be able to move the lever and linkage.

Another thing is how your boost gage is hooked up. I can't tell exactly, but heres a picture as to where it should be "T"ed from:

If that's not where it is, its wrong.

As for the vaccum lines, they appear changed. Take a picture of the boost solenoid, make sure its Subaru. Then, see if you can get a better picture of all the vaccum lines near the turbo. I feel you are missing a "t" there, as well as the section with the pill. Here's the proper layout:

Take a look, try to move the wastegate, and report back your findings It looks like just another hack that half-a$$ hooked everything back. Proably had a MBC, turbo-back exhaust. Was it by chance owed by a kid in his late teens:wiggles:

 

Honestly bro i cant thank you enough...the vacuum lines were not the same as the diagram and so i changed it to how it was...max boost .05 mpa which is 7 psi....not all the way to the top but hey it doesn't fuel cut anymore =) thanks so much!!!...whats the stock boost supposed to be at?

 

The reason your not getting all the way to .1 MPa (around 14 psi) in second gear is because you are missing the "restrictor pill" you can see it in the drawing of the vaccum lines depicted above. Its a little metal pill with a hole in it. It goes in the vaccum line at the point depicted in the picture. Just order it from subaru for like $4. Put it in, and you'll be boosting the right PSI (Mpa). .07 in second is the exact reading you'll get without the pill. Do that, and I believe you'll be golden. You can always search "restrictor pill" on this forum for a picture, and possibly even the part number to order it. Good luck, glad it appears I've helped...

Never trust a used wrx as "OEM Stock" 90% of the time, its a modded car that's been changed back to sell or warrantee

 

I called subaru and asked them about the restrictor pill and they told me that they never heard of anything like that...i told them that it was just a pill shaped piece of metal that had a hole in the middle of it and they still told me that they never heard of such a thing and that it was an aftermarket part...i called four different dealers and they all told me the same thing...is there something else that i need to know about? I tried looking for pictures of the restrictor pill and found nothing...i found one pic but it was the same thing you showed me...the only thing different was it had a yellow circle where the pill should be...

 

Ok, well first, perhaps the parts people don't really know their cars too much outside a PC Screen in a parts wharehouse...they may actually be cataloged as a "bronze orifice". Here's a picture of what it looks like:

As to where it is, here's how it looks stock (with part #):

(Ignore the restrictor mod information in the lower right corner)

Or, for a few extra #, buy the vaccum hoses, "T" and restrictor pill all as one:

Part#:14447AA090 The gold mark is where the pill goes in the hoses.

See if they understand that! If not, call this dealership in Doylestown, PA: Fred Beans Subaru: 5-Star Performance they are good, I know the sales guys there. See what you get with this information, get back to me if you hit another wall

 

You might want to check all the vacuum lines running to the boost solenoid.

What type of gas do you have around you? You might want to add some race gas and see if that solves it, then you'd know boost is a little too high for the octane you are running.

 

yup so i went to subaru today and gave them the stock number and the pic of it and they knew what it was...the only thing is they didn't know where it went but fortunately i brought the pic of where it goes too lol...i gotta wait til monday though to get the part they didnt have any in stock and the closest place was in indiana...thank you everyone for your help :wiggles:

 

Should be a no-brainer as to where it goes if the hoses are stock....theres a yellow/gold dot on the hose to show location If you don't have one on yours, just get the assembly pictured above for like $15 more. Then just plug and go!

A prime example of a dealership where the parts guy has absolutly NO idea what the heck hes talking about....first, he tells you its an "aftermarket part", then he says "oh yeah, I know THAT pill", then he says "I don't know where it goes" considering if he just plugged it into his computer, the subaru database WILL spit out a picture with part #'s. And a breakdown of the layout. Just lazy, IMO.

Good luck with your parts man!

 

Very Helpful



I would like to thank you guys so much!!! this is definately the best thread for what I am looking for! my stock 02 wrx has the same problem and all any one talks about is it not being stock... it IS!!! lol I have heard that if this doesnt fix my problem I will need a new BCS. do I have to pay $240 to get from the dealer(canada eh ) or is there an aftermarket one that I can put on for much less that will be the same? My Cobb AP tells me that I boost around 21PSI both with stock map and stage 1. Your input would be great., thanks

 

ok so i got my part in yesterday and installed it with no problem other than a few minor burns from the engine lol....as im boosting, the gauge shows that im running full boost but then when the engines starts to rev a little higher the boost drops a bit is that normal or no?? sorry for all the questions this is my first subbie :thumbup:

 

Sounds like you got it right. It should taper off a little bit. It'll hold in your higher gears (like 3rd and up). Amazing what a little bronze pill will do!

 

Since you're in the Chicago area, I HIGHLY recommend the Subbie dealership in Merrillville, IN(1 hour away). Just ask for Frank. They are very mod friendly. My friend has had a transmission fixed ($$$) under warranty with stage 2 mods no problem. If you ever plan on mods (non SPT), these guys are the best! Those Chicago ones will just say your car is VOID VOID VOID!!!