Another STFT question. Please Help!

[Civic17siYAY]

Hi everyone,

So I Posted my datalog over in the SI subthread to no response so I thought I would try here. I have been having an issue with my car throwing a code for running too rich. After looking at my STFT and LTFT I noticed that my STFT are pegged out at -25% when idling and cruising causing my LTFT after a short time to match at -25%. The code usually comes on at around -20% LTFT . Mods are PRL SRI with street MAF and ktuner OTS tune. I double checked for vacuum leaks, checked to make sure I had a street MAF and reuploaded the 19.5/21.5 PSI OTS ktuner tune as well as tried the stock "base" tune as well. Same issue. please help. Here is my most recent datalog of a quick pull down the street. You can see the STFT pegged at -25%. (I put it in a zip file because it would not let me upload it)

 

[hobby-man]

Can you try reverting to your stock intake and seeing what happens? That would give you an idea if it's your SRI or some other issue (bad MAF/O2 sensor, bad fuel injector, etc.)

 

[KTuner]

If you have a street MAF and even the factory tune produces -25% trims then you have something wrong somewhere. Likely a vacuum leak. Testing with the factory intake would be a great idea.

 

[Civic17siYAY]

I'll report back in 20 minutes when I swap intakes.

 

[Civic17siYAY]

Update: stock intake back in. Still idling at -25%

 

[KTuner]

.59 knock control suggests you haven't flashed back to factory, so either you loaded a tune that has PRL RACE selected for MAF calibration or you have an actual issue to track down. Hope you find it!

 

[Civic17siYAY]

.59 knock control suggests you haven't flashed back to factory, so either you loaded a tune that has PRL RACE selected for MAF calibration or you have an actual issue to track down. Hope you find it!

Im on the 19/21.5 OTS tune now with stock airbox. I flashed it after realizing I was having the same problem with and without the OTS tune. Ill flash back to stock now and see if that changes anything.

 

[zhendexing]

Make sure you didn’t select prl race maf under “maf scaling”. If your maf scaling was stock maf and still get -25%, probably a leak somewhere, or a dirty maf sensor. Oil from oil filter might get to the maf sensor, considering how close the air filter is to the maf sensor.

 

[Civic17siYAY]

Make sure you didn’t select prl race maf under “maf scaling”. If your maf scaling was stock maf and still get -25%, probably a leak somewhere, or a dirty maf sensor. Oil from oil filter might get to the maf sensor, considering how close the air filter is to the maf sensor.

MAF scaling is set to Factory MAF. im leaning towards buying a new MAF sensor and throwing it in to see if that fixes the problem. I hate just throwing parts at it though. Bought the car in April with 30 miles on it, has just a tad under 60k right now.

 

[zhendexing]

MAF scaling is set to Factory MAF. im leaning towards buying a new MAF sensor and throwing it in to see if that fixes the problem. I hate just throwing parts at it though. Bought the car in April with 30 miles on it, has just a tad under 60k right now.

That’s lots of mile in under a year, and performance filters are known to let more contaminants in the engine, and yea just get a new maf sensor see if it fixes the problem.

 

[Civic17siYAY]

That’s lots of mile in under a year, and performance filters are known to let more contaminants in the engine, and yea just get a new maf sensor see if it fixes the problem.

Yeah I drive a lot for work. Lol will do, I'm going to run over to autozone now and get some cleaner and order a new one.

 

[gtman]

60K in less than a year? Wow. That's 6-7 years of driving for some folks.

 

[Civic17siYAY]

Flashed back to stock. STFT still stuck at -25% during Idle and light load driving. Im going to bring the car to the dealership this week and see if they can figure it out. Also, I accidently unplugged the MAF while checking for vacuum leaks while the car was running and it kept running which I found odd... shouldn't it die after a couple seconds?

 

[zhendexing]

I saw the pictures you post on another thread, your engine bay is so dusty from the 60k/yr driving. And from the Datalog, the stft reading are mostly -25% and 0, I still think it might just be a faulty maf sensor. I also wonder how many miles you drove on the SRI before getting the CEL? Might be a bad O2 sensor as well. Anyway, your dealer is probably your best bet. Hope your problem gets solved soon.

 

[Civic17siYAY]

And

I saw the pictures you post on another thread, your engine bay is so dusty from the 60k/yr driving. And from the Datalog, the stft reading are mostly -25% and 0, I still think it might just be a faulty maf sensor. I also wonder how many miles you drove on the SRI before getting the CEL? Might be a bad O2 sensor as well. Anyway, your dealer is probably your best bet. Hope your problem gets solved soon.

Thank you. I'm leaning towards the MAF sensor as well. I'll let everyone know once they figure it out.

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