IW STi Forum banner

1 - 20 of 50 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter · #1 ·
I have a 2017 Subaru Wrx Sti, car is stock except it has an invidia catted downpipe on stock tune. Car is currently stuttering when trying to accelerate and is only boosting to 9psi , loss of power. No engine lights.
 

·
Registered
Joined
·
10 Posts
If I'm not mistaken... You'll need a tune for that. Based solely on everything I've read with anything modded for exhaust or intake.
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #3 ·
If I'm not mistaken... You'll need a tune for that. Based solely on everything I've read with anything modded for exhaust or intake.
Yes my ap is in the mail right now just waiting for it to arrive. I’m driving slow atm and trying to stay out of boost , just wondering if the downpipe is what has caused the car to go into what seems like Limp mode.
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #5 ·
adding a downpipe is likely the cause of this, you should honestly stop driving it until it gets tuned.
I have stopped driving it now until the ap arrives in the mail. Thank you for the response I am hoping the dp is the cause of this issue as it didn’t start right away started after a week then I reset the car was fine again for a day then started again and that’s when I stopped driving it and ordered the Ap
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #9 ·
The Subaru community should have access to new WRX and STI buyers and make sure they get their "packet" in the mail of things to do and don't do. Ugh.

Aftermarket downpipe on stock tune = problems.
Appreciate the reply! I bought the car with the downpipe installed already, previous owner removed the tune before selling. I picked up the car and this issue started a week after. Started reading up and saw people saying could be issues running dp on stock tune. Was trying to clarify if this issue was directly related to the downpipe with no tune. Since the issue started I havnt drove the car and ordered an accesport from Cobb. Waiting for it in the mail right now and not driving car anymore. Hoping this tune resolves this issue.
 

·
Registered
2020 WRX STI, Magnetite grey,
Joined
·
137 Posts
Oh boy… Another possible ticking time bomb. No wonder these cars get so much hate on blown motors. Why would not the previous owner either give tune/tuner with car or put stock dp back on so it runs properly? Previous owner being cheap. Warning warning. Compression check for sure. I hope yours is ok OP.
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #11 ·
Oh boy… Another possible ticking time bomb. No wonder these cars get so much hate on blown motors. Why would not the previous owner either give tune/tuner with car or put stock dp back on so it runs properly? Previous owner being cheap. Warning warning. Compression check for sure. I hope yours is ok OP.
That’s a good question, I’m not sure he still had the stock dp anymore as I seen him posting in a local Subaru group looking fr a stock dp before he sold the car and he simply said he sold his ap separately
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #12 ·
Oh boy… Another possible ticking time bomb. No wonder these cars get so much hate on blown motors. Why would not the previous owner either give tune/tuner with car or put stock dp back on so it runs properly? Previous owner being cheap. Warning warning. Compression check for sure. I hope yours is ok OP.
Getting compression test done today and diagnoses at Subaru
 

·
Registered
2017 STI
Joined
·
9 Posts
Yes my ap is in the mail right now just waiting for it to arrive. I’m driving slow atm and trying to stay out of boost , just wondering if the downpipe is what has caused the car to go into what seems like Limp mode.
Do you have your cruise control flashing on the dash? Mine went into limp mode and that started flashing. It also would not let me change the SI drive mode at all. Is it letting you accelerate at all? Mine wouldn't let me go over 2500 RPM so max speed was like 30 mph.

Mine ended up being a loose connection at the bulkhead connector. Did you install the downpipe or have a shop do it? Maybe that connection got moved a little since it is on the same side as the downpipe.
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #14 ·
Do you have your cruise control flashing on the dash? Mine went into limp mode and that started flashing. It also would not let me change the SI drive mode at all. Is it letting you accelerate at all? Mine wouldn't let me go over 2500 RPM so max speed was like 30 mph.

Mine ended up being a loose connection at the bulkhead connector. Did you install the downpipe or have a shop do it? Maybe that connection got moved a little since it is on the same side as the downpipe.
Shop installed it for previous owner as he was running stage 2 tune no issues. I got the car and it was put back on stock tune prior to selling but kept the invidia catted downpipe installed. No lights on no engine light or codes. Car does accelerate its just significantly slower and would only hit 9psi boost maximum. Under acceleration is not smooth either little stuttering / hesitation. Getting diagnoses and compression test done today at the local Subaru pfaff dealer. Hoping it’s just the car not liking the downpipe on the stock tune and hoping engine is fine. Will flash stage 2 Cobb when it arrives as long as the engine is good
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #15 ·
Getting compression test done today and diagnoses at Subaru
Oh boy… Another possible ticking time bomb. No wonder these cars get so much hate on blown motors. Why would not the previous owner either give tune/tuner with car or put stock dp back on so it runs properly? Previous owner being cheap. Warning warning. Compression check for sure. I hope yours is ok OP.
Compression test 170 for cylinders 1,2,3, 130 in cylinder 4
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #16 ·
adding a downpipe is likely the cause of this, you should honestly stop driving it until it gets tuned.
Cause wasn’t the downpipe but is the fact cylinder 4 compression is 130 rest are 170. Subaru tech said it was driven at 240km/h , 7500 rpm and 20psi on a poor tune is what caused this problem
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #17 ·
Oh boy… Another possible ticking time bomb. No wonder these cars get so much hate on blown motors. Why would not the previous owner either give tune/tuner with car or put stock dp back on so it runs properly? Previous owner being cheap. Warning warning. Compression check for sure. I hope yours is ok OP.
Going to try and return it to the dealer as I’ve had it only 3 weeks wish me the best
 

·
Registered
2020 WRX STI, Magnetite grey,
Joined
·
137 Posts
Sorry Man I feel yeah. But no surprise why the previous owner dumped it. That is 8-10k out of pocket minimum to the person/dealer that has to fix it. Very expensive learning lesson on buying used performance stuff. Damn…
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #19 ·
Sorry Man I feel yeah. But no surprise why the previous owner dumped it. That is 8-10k out of pocket minimum to the person/dealer that has to fix it. Very expensive learning lesson on buying used performance stuff. Damn…
Omg the dealer want to try and fix the issue before letting me return it. They think it’s a restrictive cat.. even tho I told them the results of the compression test ....
 
1 - 20 of 50 Posts
Top