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4K views 32 replies 8 participants last post by  mankimenzs 
#1 ·
Intro
Hey, I just got my first Subaru about a week ago and it's got some issues. It's a 2011 WRX, I bought it from a ford dealership, and it's not stock. Whoever had it last had subs (they left the wiring in the car), gave it an aftermarket exhaust, an aftermarket BOV, and left me with the COBB access port. I've done a fair bit of research, but am far from knowing the car as well as I'd like.

Modifications
Like I said in the intro, the car isn't stock.
The speaker wires are still in the car but aren't hooked up to anything.
The exhaust is from PERRIN.
I can't see any marking from the outside, but the BOV kind of looks like it's from AVO.
It also came with a COBB access port (which I can't make a whole lot of use out of because I'm still a noob).
I know for a fact that it's on it's factory tune right now.

Check Engine Light
It will (very rarely) give me a cylinder 1 and cylinder 2 misfire as well as a low catalyst system efficiency code (I haven't made a note of what code it is exactly)
It will throw also throw a CEL on cold start sometimes, it's the P2441 code (Secondary Air Injection Switching Valve Stuck Closed (Bank 1))
I hear a lot of people just get rid of that system entirely as it's only used to pass emissions, but I figured it wouldn't hurt to mention it anyway.

Drive-ability
The CEL doesn't seem too serious, but the car still has problems on the road.
In 5th gear, 4th gear, and 3rd gear, from 3.5k rpm and up, it purges boost and pulls timing.
It will also do that in 2nd gear from around 4.5k rpm.
I have not noticed it in 1st, but I also haven't taken it above 5k rpms since I've had it.
It will also randomly drop a couple hundred rpms at idle for a split second.
When it purges the boost and pulls timing, it will only accelerate if I let off the gas and drive it in a way where it doesn't build boost.
I've also noticed that the fine knock learn stays at 0 until it starts purging and pulling, then it instantly goes to -1.41.

My Thoughts
The inconsistent idle, the purging of boost, and a hissing noise points me in the direction of a vacuum leak. But I wouldn't think that a vacuum leak would have that big of an effect on the car's drive-ability unless it was a huge vacuum leak. I also can't tell if the hissing noise is just the turbo spooling up or not. (I can't hear it until I'm under load but it's blocked out by the sound of the exhaust). I've also never had an engine code suggesting that I'm running lean, and the car has never stalled when coming to a stop or idling.
I know that this is a MAF based car and that from the factory it uses a bypass valve, so it's not going to like a BOV, but I'm not sure if just having a BOV would have this big of an effect on the drive-ability of the car.
Whatever's wrong with the car isn't catastrophic, I drove it for 8 hours straight through both highways and curvy roads with no problems, I'm just tired of having a 3k rpm redline.

My Options (according to my research and phone calls)
1) I can get the car tuned for the BOV. It would need a speed density tune and might not perform to the same standard as the stock bypass valve, but it should be a quick process and I wouldn't have to replace anything on the car.
2) I can get the BOV replaced with the stock bypass valve. I shouldn't have to tune the car afterwards, but I would still have to pay a shop to work on it since I'm on a tight schedule and am not comfortable working on the car yet (mainly because it's also my daily and I don't want to break stuff trying to learn yet)

Why I'm Here
Before I go with either option, I wanted to consult a forum to get other peoples opinions.
Later tonight I might tighten the BOV to see if that helps (I never make it above 11PSI before it starts purging)
I'm also going to have it smoke tested before I get any work done on it to make sure that it 100% isn't a vacuum leak.

Any help / advice is greatly appreciated. If I could avoid taking it to a shop without doing any major work to the car, that would be great. I'm sorry if anything in this post sounded stupid, I'm still new. Thanks!
 
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#2 ·
THIS is how you stab out an intro and or question. Absolutely well written. Well done.

Access port: will clear codes and “Probably” have/have had ecu map that is correct. Cable plugs into back of access port and then dongle end goes in block under stealing wheel.
Powers up on its own and should not do anything until you tell it to. (With key on after plug in) I would NOT download anything from it to the car unless verified by COBB s lists or the tuners name is usually associated with the tune. Again, DONT do it unless your sure.
 
#3 ·
THIS is how you stab out an intro and or question. Absolutely well written. Well done.

Access port: will clear codes and “Probably” have/have had ecu map that is correct. Cable plugs into back of access port and then dongle end goes in block under stealing wheel.
Powers up on its own and should not do anything until you tell it to. (With key on after plug in) I would NOT download anything from it to the car unless verified by COBB s lists or the tuners name is usually associated with the tune. Again, DONT do it unless your sure.
Thank you for the response. Since the post I took the car out to a safe place and played around with it a little bit. I was able to clear the codes with the access port and see the tune maps that are installed. The only one that fully mitigates all the problems is the one labeled "Stage 1 Economy v400". I can smell it running lean, but it doesn't purge boost or pull timing throughout the entire rev range. It never goes above 7lbs of boost with that tune though and I can barely get under 7 seconds 0-60. If I load any of the other tunes that give it all the boost, the BOV sounds like an elephant.
 
#7 ·
Okay, and map that seems to run best is Stage 1 Economy?

What is fie named Stage 1 ACN ?
Yep, the map that runs the best out of all 12 of them is the Stage 1 Economy Mode v400 one.
The ACN maps are for "Arizona California Nevada, aka the worst 91 fuel in the nation. The tunes are typically less aggressive than typical 91 octane maps"
All of the other tunes will get me to the 14lbs of boost, but timing starts being pulled, the BOV gets super loud, and acceleration is halted in between 3k and 4k rpms

The only issue I have with the Stage 1 Economy Mode v400 is that it's slow
 
#8 ·
Disregard, did research, its for cars running AZ and CA gas.

Re reading your first post......

No, changing BOV isn't going to magically make it all better. This is or appears to be related to tunes. As for the hiss, I believe I see it in your motor picture. There is a tube disconnected from the intake. Its kinda before the bend....
 
#9 ·
Disregard, did research, its for cars running AZ and CA gas.

Re reading your first post......

No, changing BOV isn't going to magically make it all better. This is or appears to be related to tunes. As for the hiss, I believe I see it in your motor picture. There is a tube disconnected from the intake. Its kinda before the bend....
Yeah, adjusting the BOV didn't change anything. I don't see where the tube is disconnected. If you could draw a circle around the problem area and send it back, that would be wonderful. I also think it's tune related, I'm just not sure why it's tune related. I've read that you shouldn't need a new tune with a BOV, but I still have the same problem between 3k and 4k rpm after I reset the ECU. As far as I know the BOV is the only aftermarket thing under the hood.
 
#23 ·
Hi DMV, your boost/fuel problems seem familiar. My first recommendation is read as much technical stuff as you can about the EJ25 (I read everything technical on nasioc).
Seems like there may be several things happening at once and that makes troubleshooting difficult.

First, how many miles does your car have? A well known problem is the OEM turbo inlet tearing around 100k (mine tore around 120k) and then the car runs lean and boost is all over the place once you pass 0 psi . The problem is you usually can't see the tear. It only becomes visible when you remove the turbo inlet.

Second, have you checked the spark plugs AND are they the correct ones? When I bought my 2006 WRX the last service shop changed the plugs but used the Impreza plug instead of the WRX plug. The difference is significant. The gaps are around 0.040" and 0.025" (don't quote me), but the point is I had several misfires when I went into boost and/or at high RPM.

Third, are you certain you are running an official COBB map? Download the manual and read it. Then restore the official COBB maps on the accessport and choose the one that best matches your setup (probably stage 1 91 oct).

Fourth, do you have enough fuel? Is the fuel pump due for a change/upgrade and has the filter been replaced? If you're planning on keeping the car a while, I would recommend a 255+ lph pump and a steel mesh filter.


Last but not least, I am in Pittsburgh, PA and started an engine building shop last winter.

Good luck with your diagnostics.

Tony
 
#24 ·
Hi DMV, your boost/fuel problems seem familiar. My first recommendation is read as much technical stuff as you can about the EJ25 (I read everything technical on nasioc).
Seems like there may be several things happening at once and that makes troubleshooting difficult.

First, how many miles does your car have? A well known problem is the OEM turbo inlet tearing around 100k (mine tore around 120k) and then the car runs lean and boost is all over the place once you pass 0 psi . The problem is you usually can't see the tear. It only becomes visible when you remove the turbo inlet.

Second, have you checked the spark plugs AND are they the correct ones? When I bought my 2006 WRX the last service shop changed the plugs but used the Impreza plug instead of the WRX plug. The difference is significant. The gaps are around 0.040" and 0.025" (don't quote me), but the point is I had several misfires when I went into boost and/or at high RPM.

Third, are you certain you are running an official COBB map? Download the manual and read it. Then restore the official COBB maps on the accessport and choose the one that best matches your setup (probably stage 1 91 oct).

Fourth, do you have enough fuel? Is the fuel pump due for a change/upgrade and has the filter been replaced? If you're planning on keeping the car a while, I would recommend a 255+ lph pump and a steel mesh filter.


Last but not least, I am in Pittsburgh, PA and started an engine building shop last winter.

Good luck with your diagnostics.

Tony
Thank you for your feedback, I'll start looking into the technical stuff behind the EJ25.

First, my car has a little over 150k miles so I'll definitely do some research on the turbo inlet. The boost isn't all over the place, it just seems like it's consistently limited. I floored it on the highway yesterday and it held a consistent 7.14lbs of boost.

Second, I have not checked the spark plugs, at the time of me posting the initial post I had only had the car for a few days. Shortly after, the turbo feed line sprung a leak and I had to wait a week for the part to come in, so I haven't been able to spend a lot of time with the car since I've had it. I'll check them at some point, but I'm not noticing any misfires and the misfire codes haven't came up more than once since I've had the car. It does pop if I let off the gas suddenly after letting it build boost in 1st-3rd, but between the blow off valve and exhaust, I think that might be normal. I know for a fact that my exhaust doesn't have cats.

Third, I am 90% sure that I'm running an official map. I restored the "off the shelf tunes" and went through all of them to see which ones would work. The only one that doesn't give me boost problems is the Stage 1 Economy Mode v400 tune.

Fourth, I do suspect fuel problems. I have no clue if the pump has been changed or if the filter has been replaced at all over the 150k miles this car has on it. When I look at the fuel pump load gauge, it hit's 100% at 30% throttle.

Thank you for the luck and feedback, I want to take this car through all 50 states at some point, so I might fly through Pittsburgh PA in the future.
 
#25 ·
Update:
I decided that it was most likely a vacuum leak, so me and a friend took apart the intake all the way down to the turbo and put it back together. We found several loose hose clamps, upon putting everything back together nice and tight, the car runs better than ever! However now I'm hitting upwards of 20lbs of boost and will even get a "boost limit exceeded" code if I push it hard in 5th
 
#28 ·
Intro
Hey, I just got my first Subaru about a week ago and it's got some issues. It's a 2011 WRX, I bought it from a ford dealership, and it's not stock. Whoever had it last had subs (they left the wiring in the car), gave it an aftermarket exhaust, an aftermarket BOV, and left me with the COBB access port. I've done a fair bit of research, but am far from knowing the car as well as I'd like.

Modifications
Like I said in the intro, the car isn't stock.
The speaker wires are still in the car but aren't hooked up to anything.
The exhaust is from PERRIN.
I can't see any marking from the outside, but the BOV kind of looks like it's from AVO.
It also came with a COBB access port (which I can't make a whole lot of use out of because I'm still a noob).
I know for a fact that it's on it's factory tune right now.

Check Engine Light
It will (very rarely) give me a cylinder 1 and cylinder 2 misfire as well as a low catalyst system efficiency code (I haven't made a note of what code it is exactly)
It will throw also throw a CEL on cold start sometimes, it's the P2441 code (Secondary Air Injection Switching Valve Stuck Closed (Bank 1))
I hear a lot of people just get rid of that system entirely as it's only used to pass emissions, but I figured it wouldn't hurt to mention it anyway.

Drive-ability
The CEL doesn't seem too serious, but the car still has problems on the road.
In 5th gear, 4th gear, and 3rd gear, from 3.5k rpm and up, it purges boost and pulls timing.
It will also do that in 2nd gear from around 4.5k rpm.
I have not noticed it in 1st, but I also haven't taken it above 5k rpms since I've had it.
It will also randomly drop a couple hundred rpms at idle for a split second.
When it purges the boost and pulls timing, it will only accelerate if I let off the gas and drive it in a way where it doesn't build boost.
I've also noticed that the fine knock learn stays at 0 until it starts purging and pulling, then it instantly goes to -1.41.

My Thoughts
The inconsistent idle, the purging of boost, and a hissing noise points me in the direction of a vacuum leak. But I wouldn't think that a vacuum leak would have that big of an effect on the car's drive-ability unless it was a huge vacuum leak. I also can't tell if the hissing noise is just the turbo spooling up or not. (I can't hear it until I'm under load but it's blocked out by the sound of the exhaust). I've also never had an engine code suggesting that I'm running lean, and the car has never stalled when coming to a stop or idling.
I know that this is a MAF based car and that from the factory it uses a bypass valve, so it's not going to like a BOV, but I'm not sure if just having a BOV would have this big of an effect on the drive-ability of the car.
Whatever's wrong with the car isn't catastrophic, I drove it for 8 hours straight through both highways and curvy roads with no problems, I'm just tired of having a 3k rpm redline.

My Options (according to my research and phone calls)
1) I can get the car tuned for the BOV. It would need a speed density tune and might not perform to the same standard as the stock bypass valve, but it should be a quick process and I wouldn't have to replace anything on the car.
2) I can get the BOV replaced with the stock bypass valve. I shouldn't have to tune the car afterwards, but I would still have to pay a shop to work on it since I'm on a tight schedule and am not comfortable working on the car yet (mainly because it's also my daily and I don't want to break stuff trying to learn yet)

Why I'm Here
Before I go with either option, I wanted to consult a forum to get other peoples opinions.
Later tonight I might tighten the BOV to see if that helps (I never make it above 11PSI before it starts purging)
I'm also going to have it smoke tested before I get any work done on it to make sure that it 100% isn't a vacuum leak.

Any help / advice is greatly appreciated. If I could avoid taking it to a shop without doing any major work to the car, that would be great. I'm sorry if anything in this post sounded stupid, I'm still new. Thanks!
My 2015 limited has these very similar problems, I also have a possible clutch problem too, when I take my foot off in firstt shell bog right down and almost stall, I have to slam the clutch back in and Rev it a bit or it will barely catch and spool late with a super thrust of turbo....
 
#31 ·
For your modified 2011 Subaru WRX, tackle performance problems by checking for vacuum leaks and consider reverting to the stock bypass valve instead of the aftermarket Blow-Off Valve (BOV) to restore proper air-fuel ratios. Address Check Engine Light (CEL) codes promptly, especially misfire and catalyst issues, to prevent potential engine damage. Seek professional help from a Subaru specialist or performance shop for accurate diagnosis and repairs, and tap into the Subaru community for additional insights.
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#32 ·
Intro
Hey, I just got my first Subaru about a week ago and it's got some issues. It's a 2011 WRX, I bought it from a ford dealership, and it's not stock. Whoever had it last had subs (they left the wiring in the car), gave it an aftermarket exhaust, an aftermarket BOV, and left me with the COBB access port. I've done a fair bit of research, but am far from knowing the car as well as I'd like.

Modifications
Like I said in the intro, the car isn't stock.
The speaker wires are still in the car but aren't hooked up to anything.
The exhaust is from PERRIN.
I can't see any marking from the outside, but the BOV kind of looks like it's from AVO.
It also came with a COBB access port (which I can't make a whole lot of use out of because I'm still a noob).
I know for a fact that it's on it's factory tune right now.

Check Engine Light
It will (very rarely) give me a cylinder 1 and cylinder 2 misfire as well as a low catalyst system efficiency code (I haven't made a note of what code it is exactly)
It will throw also throw a CEL on cold start sometimes, it's the P2441 code (Secondary Air Injection Switching Valve Stuck Closed (Bank 1))
I hear a lot of people just get rid of that system entirely as it's only used to pass emissions, but I figured it wouldn't hurt to mention it anyway.

Drive-ability
The CEL doesn't seem too serious, but the car still has problems on the road.
In 5th gear, 4th gear, and 3rd gear, from 3.5k rpm and up, it purges boost and pulls timing.
It will also do that in 2nd gear from around 4.5k rpm.
I have not noticed it in 1st, but I also haven't taken it above 5k rpms since I've had it.
It will also randomly drop a couple hundred rpms at idle for a split second.
When it purges the boost and pulls timing, it will only accelerate if I let off the gas and drive it in a way where it doesn't build boost.
I've also noticed that the fine knock learn stays at 0 until it starts purging and pulling, then it instantly goes to -1.41.

My Thoughts
The inconsistent idle, the purging of boost, and a hissing noise points me in the direction of a vacuum leak. But I wouldn't think that a vacuum leak would have that big of an effect on the car's drive-ability unless it was a huge vacuum leak. I also can't tell if the hissing noise is just the turbo spooling up or not. (I can't hear it until I'm under load but it's blocked out by the sound of the exhaust). I've also never had an engine code suggesting that I'm running lean, and the car has never stalled when coming to a stop or idling.
I know that this is a MAF based car and that from the factory it uses a bypass valve, so it's not going to like a BOV, but I'm not sure if just having a BOV would have this big of an effect on the drive-ability of the car.
Whatever's wrong with the car isn't catastrophic, I drove it for 8 hours straight through both highways and curvy roads with no problems, I'm just tired of having a 3k rpm redline.

My Options (according to my research and phone calls)
1) I can get the car tuned for the BOV. It would need a speed density tune and might not perform to the same standard as the stock bypass valve, but it should be a quick process and I wouldn't have to replace anything on the car.
2) I can get the BOV replaced with the stock bypass valve. I shouldn't have to tune the car afterwards, but I would still have to pay a shop to work on it since I'm on a tight schedule and am not comfortable working on the car yet (mainly because it's also my daily and I don't want to break stuff trying to learn yet)

Why I'm Here
Before I go with either option, I wanted to consult a forum to get other peoples opinions.
Later tonight I might tighten the BOV to see if that helps (I never make it above 11PSI before it starts purging)
I'm also going to have it smoke tested before I get any work done on it to make sure that it 100% isn't a vacuum leak.

Any help / advice is greatly appreciated. If I could avoid taking it to a shop without doing any major work to the car, that would be great. I'm sorry if anything in this post sounded stupid, I'm still new. Thanks!
you made me go back to my post and reread it to not suck as bad lol thank you, great write up.
 
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