High LTFT on Ktuner basemap 19.5/23

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What I'd like to see is you temporarily going back to the stock intake and re-flashing the KTuner basemap. Then run and post a datalog of 20-30 minutes of mixed driving.​
I know that's a bunch of work for you but I'd like to look at your trims on that log. IMO, there is virtually no way the tune is the culprit to your -17 LTFT. Those tunes were designed and optimized on a a stock 1.5 turbo.​
This might be one of those process of elimination things.​
This is the right way to go about it. From what I've seen on this forum, most people struggling with consistent and excessively high LTFTs is leaking injectors. Using the stock tune will help sus that out.
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Put the stock intake on and saw the same result as with the PRL street cai on the factory tune. I guess I can rule out the intake causing the problem. I put a datalog with some highway driving and city street below if anyone can take a gander at it or help.
 

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You're welcome to get a second opinion but I'm not sure what all this concern is about. For most of the drive LTFT was at -4 or better. After the full 48 minute drive it was at -7 mostly because of the inordinate amount of idling. It's not unusual for our cars to idle rich.

It's interesting to see how high KC is on the stock tune. Of course that's Honda being over protective.

Honda Civic 10th gen High LTFT on Ktuner basemap 19.5/23 Screenshot 2020-12-09 213005
 
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You're welcome to get a second opinion but I'm not sure what all this concern is about. For most of the drive LTFT was at -4 or better. After the full 48 minute drive it was at -7 mostly because of the inordinate amount of idling. It's not unusual for our cars to idle rich.

It's interesting to see how high KC is on the stock tune. Of course that's Honda being over protective.

Screenshot 2020-12-09 213005.jpg
I didn't review the log myself but assuming gtman's findings are accurate (certainly not his first log!) I agree there is nothing to worry about here.
 
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You're welcome to get a second opinion but I'm not sure what all this concern is about. For most of the drive LTFT was at -4 or better. After the full 48 minute drive it was at -7 mostly because of the inordinate amount of idling. It's not unusual for our cars to idle rich.

It's interesting to see how high KC is on the stock tune. Of course that's Honda being over protective.

Screenshot 2020-12-09 213005.jpg
Should I give the Ktuner basemap a try then? I’m not entirely sure how I could’ve reached a ltft of -20 at the time but I could give it another go.
 


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Yep. Load it up and post up another datalog. Stock intake.

If the trims are OK, that may mean the original issue could be related to your PRL in some way.

Again, just remember, the more important number is LTFT, not the ever changing STFT.
 
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Yep. Load it up and post up another datalog. Stock intake.

If the trims are OK, that may mean the original issue could be related to your PRL in some way.

Again, just remember, the more important number is LTFT, not the ever changing STFT.
Basemap on the Ktuner starter 19.5/23 mostly highway and a little city street. I guess my last question is how do I circumvent the high negative ltft if I drive local a lot in stop and go traffic? (I'm thinking that contributed to me seeing -20 ltft a few days ago)
 

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Ok, so I checked your latest datalog. Everything is nearly identical to your stock datalog. LTFTs were at -7 at the end of the drive which is perfectly acceptable.

Honda Civic 10th gen High LTFT on Ktuner basemap 19.5/23 Capture.JPG


Now the next step is putting the PRL intake back on and doing another datalog. If that looks good, it's possible the high LTFTs you originally saw may have been a glitch of some sort.
 
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Ok, so I checked your latest datalog. Everything is nearly identical to your stock datalog. LTFTs were at -7 at the end of the drive which is perfectly acceptable.

Capture.JPG


Now the next step is putting the PRL intake back on and doing another datalog. If that looks good, it's possible the high LTFTs you originally saw may have been a glitch of some sort.
Will do! I had a quick question, does flashing the car and then driving over the course of a single driving session make it more susceptible to change or does leaving the flash for a couple days average out the ltft over a period of time? (Update: I hit -17 ltft after sitting in traffic for 30 minutes on the factory tune, I'm not sure if this is problematic but I thought I'd mention it)
 
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Seems like the thread died but if anyone sees this in the future and had the same worries as me, the high ltft sitting in traffic went away after leaving the tune on the car for a week and changing the regular place I get gas from. (Could have been bad gas, I'm not entirely sure but the problem seems to be gone.)
 
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Reviving this thread again. It turned out to be bad fuel injectors! The fuel trims gradually got worse again after a short while and hit -20 STFT and LTFT averaged -10 or more in most driving situations. Replaced the injectors and the car is running perfectly. I also noticed the car shook at idle when the fuel trims got really bad.
 

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Reviving this thread again. It turned out to be bad fuel injectors! The fuel trims gradually got worse again after a short while and hit -20 STFT and LTFT averaged -10 or more in most driving situations. Replaced the injectors and the car is running perfectly. I also noticed the car shook at idle when the fuel trims got really bad.
Was there any noticeable signs on the injectors? I'm having a similar problem.
At wide open throttle getting afrs or 9.
My ltft is around - 7 to-17 at times.
Sometimes my stft is also very negative.

Not to sure how to assess if my injector is leaking
 
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Was there any noticeable signs on the injectors? I'm having a similar problem.
At wide open throttle getting afrs or 9.
My ltft is around - 7 to-17 at times.
Sometimes my stft is also very negative.

Not to sure how to assess if my injector is leaking
Honestly, I didn't notice anything aside from the high negative STFT, LTFT, and noticeable shaking idle. If you are seeing LTFT in the -15 or higher within fifteen minutes of driving it may be your injectors, I'll try to answer any questions if you still need help ! You could get the injectors diagnosed at your local dealership but be wary if your car is modified, I had a hard time at mine.
 

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Honestly, I didn't notice anything aside from the high negative STFT, LTFT, and noticeable shaking idle. If you are seeing LTFT in the -15 or higher within fifteen minutes of driving it may be your injectors, I'll try to answer any questions if you still need help ! You could get the injectors diagnosed at your local dealership but be wary if your car is modified, I had a hard time at mine.
My local dealership is garbage and the car is lightly modified.
I was thinking to flow test the injectors and replace any of they seem to be problematic.
What I would like to know is if doing the change of injectors requires new gaskets.
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