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Discussion Starter · #1 ·
Yesterday I attended a local car meet. While accelerating from a stop I noticed the car didn’t pull like it use to.
Someone made a similar post (read it). Some say there might be a boost leak or should reset ECU. Should I reset through AP or disconnect the battery?

engine mods:
-GrimmSpeed boost controller
-SPT short ram intake
-Grimmspeed catted down pipe
-Grimmspeed TMIC Y-pipe
-IAG AOS
-Invidia exhaust
-Killer B pan and pickup
 

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2021 WRX STI
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I don't recall an instance where I ever fixed an issue solely by resetting the ECU where there wasn't another related issue IE bad sensor that I replaced/cleaned, etc.

In addition to a boost leak test as @Jay11STI recommended (boost leak tests are always a good idea), if you have logs from when the car ran well I'd pull new logs and compare.
 

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if you have logs from when the car ran well I'd pull new logs and compare.
This. Awesomely this. I'm often accused of being a data hoarder - which I probably am, by the way - but I try to keep a running backup of all of the logs from the "Black Pearl" (my STi). When things seem to look a little wonky I go to the HDD and start comparing logs (last in-first checked, then back) to see if I can detect any trends. I also leave myself "Event Notes" in the same folder(s), explaining "Oil Change at xxxx/xx/xx", or "Engine short-block rebuild at xxxx/xx/xx", "Turbo replaced at xxxx/xx/xx" so I'll know why the sudden drastic shift in data --- if there is any. (The ringland failure surprised us all! No really obvious trends for that, I'm sorry to admit.)

Of course, my background is mostly scientific, so it just comes as second nature that I'd save all of my logs and keep backups of my Tunes. Of course, reading stuff here makes me even happier that I keep backups of everything. Makes me feel like I might be doing something right! And really, how much space will ten years' worth of logs take up on a 5TB drive?
 

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haha my backup drive is mostly

Code:
config_$(date).txt
config_$(date).txt.bak
config_$(date).txt.bak1
config_$(date).txt.bak2
because I'm paranoid about borking something. lol So anytime I change something I pull a backup of the config before changing it.. XD
 

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Discussion Starter · #7 ·
This. Awesomely this. I'm often accused of being a data hoarder - which I probably am, by the way - but I try to keep a running backup of all of the logs from the "Black Pearl" (my STi). When things seem to look a little wonky I go to the HDD and start comparing logs (last in-first checked, then back) to see if I can detect any trends. I also leave myself "Event Notes" in the same folder(s), explaining "Oil Change at xxxx/xx/xx", or "Engine short-block rebuild at xxxx/xx/xx", "Turbo replaced at xxxx/xx/xx" so I'll know why the sudden drastic shift in data --- if there is any. (The ringland failure surprised us all! No really obvious trends for that, I'm sorry to admit.)

Of course, my background is mostly scientific, so it just comes as second nature that I'd save all of my logs and keep backups of my Tunes. Of course, reading stuff here makes me even happier that I keep backups of everything. Makes me feel like I might be doing something right! And really, how much space will ten years' worth of logs take up on a 5TB drive?
I don't recall an instance where I ever fixed an issue solely by resetting the ECU where there wasn't another related issue IE bad sensor that I replaced/cleaned, etc.

In addition to a boost leak test as @Jay11STI recommended (boost leak tests are always a good idea), if you have logs from when the car ran well I'd pull new logs and compare.
Good idea.

I have not plugged my AP in the computer yet. Plug the AP in the pc then extract data? Easy as that?

There is a chance I’ve not been logging data when it was pulling normal.
 

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As everyone has said. Boost test to start.
Logs are key. Get a good long once a month or so (can do it more if you’d like) to see trends long term. Keep in mind. At some point you’ll get used to the power, and it’ll start to feel slower when it’s actually not. Lol. Mainly cause your brain will remember the initial rush when you aren’t used to it. But when you get used to it, you don’t feel that as much. Hence why everyone gets power hungry lol.
 

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Procedure please?
Nissanfanatic pretty much link'd it for you. You can either make your own boost leak tester or purchase a pre made one. I have one myself from Dave at turboboostleaktesters.com and has worked well for me.

There are many reason why the car didnt pull as hard for you that one time. Its just too vauge without enough information. AP data logging is great and all but it cant correct a mechanical problem. Id personally verify that things are mechanically well first before beating on the car for data logs.
 

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Discussion Starter · #11 · (Edited)
Nissanfanatic pretty much link'd it for you. You can either make your own boost leak tester or purchase a pre made one. I have one myself from Dave at turboboostleaktesters.com and has worked well for me.

There are many reason why the car didnt pull as hard for you that one time. Its just too vauge without enough information. AP data logging is great and all but it cant correct a mechanical problem. Id personally verify that things are mechanically well first before beating on the car for data logs.
I reset the ECU, cars back to normal. I will start recording AP data.

Edit: Car isn’t running right after letting it sit.
 

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Discussion Starter · #15 ·
Hmm doesn't seem like anything that would make a considerable difference. But, "boost weather" is definitely a thing IE 40*F vs 85-90*F.
It didn’t get up to 85*F. Sometimes the AP says having difficult connecting. Maybe the AP doesn’t talk to the ECU at times.

I turn on the AP on before starting the car. Does it matter when I start the AP?
 

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It didn’t get up to 85*F. Sometimes the AP says having difficult connecting. Maybe the AP doesn’t talk to the ECU at times.

I turn on the AP on before starting the car. Does it matter when I start the AP?
Not at all.

Like others have suggested do some data logging and check for leaks. I use a smoke tester. Easier to use than a boost leak tester IMO. You can pick them up fairly cheap as well.
 

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Discussion Starter · #18 · (Edited)
Lol. Warmer air. It is not January right now. Ambient temps affect “gas” turbo cars significantly. That is why E85 tuned cars are the shizzle in summer temps.
I am telling you it wasn’t even warm outside. Haha.

I need to look over the data though. I took the car out for a few runs before and after reflashing the ECU.

Edit: I don’t think the reflash helped… I drove the car again and doesn’t feel quite right. I will have to perform a boost test.
 

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Discussion Starter · #19 ·
Not at all.

Like others have suggested do some data logging and check for leaks. I use a smoke tester. Easier to use than a boost leak tester IMO. You can pick them up fairly cheap as well.
Do you use the smoke tester while the car is idling or mount in the engine bay then run the car on the road?
 
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