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Old 09-14-2020, 04:44 PM   #1
Ssinclair77
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Join Date: May 2020
Location: Ontario, Canada
Vehicle:
2016 WRX Base
Lapis Blue

Exclamation Stage 1 WRX running extremely lean

The car has: TGV/EGR deletes, AEM intake, catback and COBB EBCS.

75% of the time the car runs fine. 25% of the time the AP shows the car leaning out to 18:1 and runs very poor. I pull over and restart the car/change to earlier MAP but it does not fix the issue. If I get into boost again the AF goes back down to 10.14. The leaning out only seems to happen when the car is not completely warmed up. Once the car is up to temp and has been running for a while it never seems to be an issue. I can't replicate the issue unless I let the car sit for hours, then start it and try to drive again.

Sometimes when the car is cold and I start it to warm up it throws a code for "extreme rich", if I clear it the code does not come back while driving.

I have changed the spark plugs, cleaned the MAF and MAP sensors, checked the MAF voltage, had 2 shops perform smoke tests on the intake and sent logs to my tuner. The tuner still believes that my issue is a leak between the turbo and the heads.

I am wondering what my next steps should be? I am thinking of adding a wideband sensor and or replacing my O2 sensors. Last resort is to buy a new speed density tune.

Link to datalog: https://imgur.com/gallery/1aThVsJ?s=sms

Edit: The AF learning has gotten much better (-8.59%) but nothing has been changed on the car since I took that datalog.
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Last edited by Ssinclair77; 09-14-2020 at 04:47 PM. Reason: Adding info.
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Old 09-14-2020, 06:36 PM   #2
Rexy18
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Maybe use proper intake with proper mapping. Maybe purchase proper custom tune. Youre not giving us enough info or a log/data. 8% af correction when? I have 20/10 so 30% max correction swings and no bucking. <3% correction under heavy load and 1% at wot. What tune are you running now and why hasnt this been addressed during tuning, or if it has been then how?
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Old 09-14-2020, 07:34 PM   #3
subaru_gc8
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2004 WRX wagon
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Quote:
Originally Posted by Ssinclair77 View Post
The car has: TGV/EGR deletes, AEM intake, catback and COBB EBCS.

75% of the time the car runs fine. 25% of the time the AP shows the car leaning out to 18:1 and runs very poor. I pull over and restart the car/change to earlier MAP but it does not fix the issue. If I get into boost again the AF goes back down to 10.14. The leaning out only seems to happen when the car is not completely warmed up. Once the car is up to temp and has been running for a while it never seems to be an issue. I can't replicate the issue unless I let the car sit for hours, then start it and try to drive again.

Sometimes when the car is cold and I start it to warm up it throws a code for "extreme rich", if I clear it the code does not come back while driving.

I have changed the spark plugs, cleaned the MAF and MAP sensors, checked the MAF voltage, had 2 shops perform smoke tests on the intake and sent logs to my tuner. The tuner still believes that my issue is a leak between the turbo and the heads.

I am wondering what my next steps should be? I am thinking of adding a wideband sensor and or replacing my O2 sensors. Last resort is to buy a new speed density tune.

Link to datalog: https://imgur.com/gallery/1aThVsJ?s=sms

Edit: The AF learning has gotten much better (-8.59%) but nothing has been changed on the car since I took that datalog.
Im thinking you are running lean because you got tgv deletes. when you car is cold the tgv restrict air going into the engine. so they are half way closed. so since you got rid of then you are getting full flow and its allowing too much air into the engine. so mu nex question is are you using a off the shelf map or are you actually tuned for the things you have.
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Old 09-14-2020, 08:13 PM   #4
dusty_sombero
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Quote:
Originally Posted by Ssinclair77 View Post
The car has: TGV/EGR deletes, AEM intake, catback and COBB EBCS.

75% of the time the car runs fine. 25% of the time the AP shows the car leaning out to 18:1 and runs very poor. I pull over and restart the car/change to earlier MAP but it does not fix the issue. If I get into boost again the AF goes back down to 10.14. The leaning out only seems to happen when the car is not completely warmed up. Once the car is up to temp and has been running for a while it never seems to be an issue. I can't replicate the issue unless I let the car sit for hours, then start it and try to drive again.

Sometimes when the car is cold and I start it to warm up it throws a code for "extreme rich", if I clear it the code does not come back while driving.

I have changed the spark plugs, cleaned the MAF and MAP sensors, checked the MAF voltage, had 2 shops perform smoke tests on the intake and sent logs to my tuner. The tuner still believes that my issue is a leak between the turbo and the heads.

I am wondering what my next steps should be? I am thinking of adding a wideband sensor and or replacing my O2 sensors. Last resort is to buy a new speed density tune.

Link to datalog: https://imgur.com/gallery/1aThVsJ?s=sms

Edit: The AF learning has gotten much better (-8.59%) but nothing has been changed on the car since I took that datalog.
Who’s the tuner?
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Old 09-15-2020, 09:31 AM   #5
Mike1Juliet
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You have a stage 1 OTS tune and you have EGR deletes? How'd you overcome the CEL? What do you mean "Change over to MAP"? Like you have an MAPerformance off-the-shelf tune?
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Old 09-15-2020, 10:44 AM   #6
noobultimatum
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ALL THE STAGES

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inb4 kaboom thread
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Old 09-15-2020, 10:50 AM   #7
JP Chestnut
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My general feeling is that these Subaru engines aren't very durable. However, threads like this make me suspect that the vast majority of the issues are due to user error.
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Old 09-15-2020, 11:26 AM   #8
Mike1Juliet
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Quote:
Originally Posted by JP Chestnut View Post
My general feeling is that these Subaru engines aren't very durable. However, threads like this make me suspect that the vast majority of the issues are due to user error.
Thats basically what I got out of the Engine Failure thread. The only people who are getting engine failure are those that beat the snot out of their engine and also installed bad mods, bad tunes or made bad choices otherwise. There are actually very few people who had stock engines with stock oil, etc who had engine failure due to factory defect or something.
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Old 09-15-2020, 03:32 PM   #9
noobultimatum
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Quote:
Originally Posted by JP Chestnut View Post
My general feeling is that these Subaru engines aren't very durable. However, threads like this make me suspect that the vast majority of the issues are due to user error.
BINGO
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Old 09-15-2020, 04:47 PM   #10
BostonShaun
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Quote:
Originally Posted by JP Chestnut View Post
My general feeling is that these Subaru engines aren't very durable. However, threads like this make me suspect that the vast majority of the issues are due to user error.
The FA20 is more durable than you think, its just that you see a small percentage of people talking about engine failures on a Subaru specific forum and/or facebook groups/ect.

You're second point is correct, and it gets even worse when you start questioning some of the people that have failures and figure out they have no idea about modding/tuning/maintenance/driving a boosted vehicle in general.
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Old 09-15-2020, 05:32 PM   #11
gn4rwhals
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"The tuner still believes that my issue is a leak between the turbo and the heads."

Check the header bolts, they are known to come loose over time and cause crazy behavior. There is a TSB out by Subaru to address it.
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Old 09-15-2020, 06:25 PM   #12
WMTwrx15
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Quote:
Originally Posted by noobultimatum View Post
BINGO

I second this motion!
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Old 09-15-2020, 07:30 PM   #13
JP Chestnut
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Quote:
Originally Posted by BostonShaun View Post
The FA20 is more durable than you think, its just that you see a small percentage of people talking about engine failures on a Subaru specific forum and/or facebook groups/ect.

You're second point is correct, and it gets even worse when you start questioning some of the people that have failures and figure out they have no idea about modding/tuning/maintenance/driving a boosted vehicle in general.
It's weird though, because there are tons of easily modded turbo cars floating around that aren't Subarus, yet their owners manage to read Cobb's instructions and load the correct maps with regularity. There's clearly a selection effect going on with WRX owners.
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Old 09-16-2020, 01:00 PM   #14
t00sl0w
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Quote:
Originally Posted by JP Chestnut View Post
It's weird though, because there are tons of easily modded turbo cars floating around that aren't Subarus, yet their owners manage to read Cobb's instructions and load the correct maps with regularity. There's clearly a selection effect going on with WRX owners.

I'd argue the popularity and success of the early WRX has brought a lot of people who shouldnt be modifying cars due to either their inability to read/follow directions or a lack of common sense in the automotive world.


heck, i bought a bugeye after i graduated high school in 07 and i remember how the WRX craze was starting to skyrocket and bring in bozos even back then.
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Old 09-21-2020, 06:53 AM   #15
CGumina
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Quote:
Originally Posted by WMTwrx15 View Post
I second this motion!
Thirded.
Quote:
Originally Posted by JP Chestnut View Post
It's weird though, because there are tons of easily modded turbo cars floating around that aren't Subarus, yet their owners manage to read Cobb's instructions and load the correct maps with regularity. There's clearly a selection effect going on with WRX owners.
WRX's are considerably cheaper than GTR's, Porsches, and BMW's. Additionally, they're availability on the used market, paired with a plethora of cheap "Wish.com" quality parts is pretty overwhelming.

99% of blown up/ruined Subaru products I've encountered personally are due to user error or neglect, but they always leave out that they 'forgot the change the oil 9,000 miles ago' or that 'that intake wasn't on the list of approved parts for an off-the-shelf tune but I used it anyway because I like the whistle noises'.
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