Boost leak?

[AmaiX]

A little defeated at this point...
Dropped the car off at the dealer hoping they'd fix my "presumed boost leak", and also look into the U129E code (which I only get when tuned).

Went for a drive 30 minutes ago, reattached my prl cobra, tuned it to a stock 21 starter map started a datalog. It still feels as if my car hits a wall after a certain amount of boost, if someone can checkout my datalog to see what the issue is, it would be greatly appreciated. So bummed I can't enjoy my car.. need to reschedule and make it blatantly obvious next visit.

Mod list:
PRL Cobra (Street)
Remark Exhaust
Ktuner 21 Starter

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[gtman]

You were hitting your boost targets basically but you never actually went WOT on the log.

 

[KTuner]

U129E is a test option under disables.

Not going full throttle is way more common than you'd expect.

 

[AmaiX]

You were hitting your boost targets basically but you never actually went WOT on the log.

Appreciate you checking it out sir!!
I’ve noticed once I hit a certain amount of boost (11 psi) the number becomes static on the Ktuner, and the value will not increase. It also prompts Ktuner to start a auto-data log

 

[gtman]

Try running a datalog making sure you do a couple pulls where you keep the throttle to the floor for a bit. Make sure you're on the 21psi map.

 

[AmaiX]

Try running a datalog making sure you do a couple pulls where you keep the throttle to the floor for 15+ seconds. Make sure you're on the 21psi map.

Will do! Id like to mention I’ve never once seen my stft positive whilst on throttle, is that not an issue?

 

[gtman]

That just means you run slightly rich and with a turbo that's not necessarily a bad thing honestly.

 

[AmaiX]

That just means you run a bit rich and with a turbo that's not a bad thing honestly.

Greatly appreciate your insight! Thank you sir ?? Will try to get some pulls in later in the day. Hawaii is a little too hot, and humid during the daytime.

 

[AmaiX]

Finally had time to get in a datalog, I did notice there was a misfire in cylinder 2.

 

[RehabJP]

Finally had time to get in a datalog, I did notice there was a misfire in cylinder 2.

If your running the 1.5T that is a well known issue. I had similar concerns about misfire in my Si but its common and probably not true misfires. Something to do with the knock sensor on these things being very sensitive and they pop of. Unless your getting rapid fire misfires like literally hundreds then I would not sweat it. Basically if its not throwing a misfire MIL code then your probably fine.

 

[AmaiX]

If your running the 1.5T that is a well known issue. I had similar concerns about misfire in my Si but its common and probably not true misfires. Something to do with the knock sensor on these things being very sensitive and they pop of. Unless your getting rapid fire misfires like literally hundreds then I would not sweat it. Basically if its not throwing a misfire MIL code then your probably fine.

Phew.. Thats good to know. Appreciate the insight man. ?

 

[gtman]

Ok, so going back to the title of this thread, I absolutely don't see how you could have a boost leak. You hit your boost targets every time. The 4 "knock counts" and those couple cylinder "misfires" are nothing to worry about. Knock control was great.

I still didn't see you fully floor it based on the throttle numbers.

But here's what's concerning. Your long term trim was around -12 to -14%. That's very rich.

When I looked at your first datalog, I was concentrating on your boost leak questions. I just went back to look at the fuel trims. The fuel trims were rich but the numbers weren't nearly as bad as the second datalog.

Keep in mind I read a lot of datalogs and can tell you what I see but can't diagnose the actual issue from here.

Generally speaking, "high negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative emissions components, leaking injectors, defective O2 sensors..."

Just to throw out one thing here. Are you 100% sure you're running the street MAF and not the Race MAF (just to eliminate that issue)?

 

[AmaiX]

Ok, so going back to the title of this thread, I absolutely don't see how you could have a boost leak. You hit your boost targets every time. The 4 "knock counts" and those couple cylinder "misfires" are nothing to worry about. Knock control was great.

I still didn't see you fully floor it based on the throttle numbers.

But here's what's concerning. Your long term trim was around -12 to -14%. That's very rich.

When I looked at your first datalog, the fuel trims were rich but the numbers weren't nearly this high. Keep, in mind I read a lot of datalogs and can tell you what I see but can't diagnose the actual issue from here.

Generally speaking, "high negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative emissions components, leaking injectors, defective O2 sensors..."

Just to throw out one thing here. Are you 100% sure you're running the street MAF and not the Race MAF (just to eliminate that issue)?

I know at one point in time, months before swapping out my exhaust for my remark axleback I did throw a emissions code. Never did see it again. However readiness status shows red for evap/catalyst til this day.

I also did verify that my intake is indeed marked as “ex”, but Ill definitely re-check it in the morning before work. Possibly looking into re-oiling the intake, and cleaning the maf sensor this week. Otherwise I’ll swap to my mishimoto short ram, followed by the stock box, and monitor trims.

I appreciate the knowledge you’re providing me, always so helpful sir.

edit: verified that am indeed running street maf (ex)

 

[Gradyjim024]

Ok, so going back to the title of this thread, I absolutely don't see how you could have a boost leak. You hit your boost targets every time. The 4 "knock counts" and those couple cylinder "misfires" are nothing to worry about. Knock control was great.

I still didn't see you fully floor it based on the throttle numbers.

But here's what's concerning. Your long term trim was around -12 to -14%. That's very rich.

When I looked at your first datalog, I was concentrating on your boost leak questions. I just went back to look at the fuel trims. The fuel trims were rich but the numbers weren't nearly as bad as the second datalog.

Keep in mind I read a lot of datalogs and can tell you what I see but can't diagnose the actual issue from here.

Generally speaking, "high negative fuel trim corrections can be caused by MAF sensor problems, high fuel pressure, leaking fuel pressure regulator diaphragm, faulty evaporative emissions components, leaking injectors, defective O2 sensors..."

Just to throw out one thing here. Are you 100% sure you're running the street MAF and not the Race MAF (just to eliminate that issue)?

I'm having difficulty finding a diagram where it shows where the fuel pressure regulator goes and the numbers of it on the illustrations are different on a couple of websites. My car has thrown a p0172 code and I'm trying the maf tomorrow but I'm trying everything before the injectors.

 

[hobby-man]

I'm having difficulty finding a diagram where it shows where the fuel pressure regulator goes and the numbers of it on the illustrations are different on a couple of websites. My car has thrown a p0172 code and I'm trying the maf tomorrow but I'm trying everything before the injectors.

Do you have an aftermarket downpipe?

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