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P0171 code

Posted: Sun Nov 03, 2024 12:29 am
by Od1n
Hey guys, recently got my hands on a FN2R. Previous owner had it tuned and after purchasing the car, came back to a P0171 code and have not been able to figure it out. Car has injen CAI and Tegiwa 70mm exhaust. Have driven it for the past month with the code and have noticed rough idling. Attached is a recent datalog and the calibration it's on. Much help would be appreciated!

Re: P0171 code

Posted: Mon Nov 04, 2024 10:13 am
by Spunkster
It appears to be running too lean, and you can see it has high fuel trims. The fuel tables need to be adjusted to run richer.

Re: P0171 code

Posted: Sun Nov 10, 2024 7:23 am
by Od1n
Any idea what values I could adjust the fuel trims to? Car wasn’t tuned by me so I’m not quite sure what to adjust it to!

Re: P0171 code

Posted: Sun Nov 10, 2024 7:23 am
by Od1n
Spunkster wrote: Mon Nov 04, 2024 10:13 am It appears to be running too lean, and you can see it has high fuel trims. The fuel tables need to be adjusted to run richer.
Any idea what values to adjust it to? Not quite sure what to do here as car wasn’t tuned by me and did not have this issue according to previous owner!

Re: P0171 code

Posted: Mon Nov 11, 2024 10:10 am
by Spunkster
You need to look where it is running lean and make adjustments to those areas of the table where it is lean.

Re: P0171 code

Posted: Wed Mar 12, 2025 7:40 pm
by Od1n
Spunkster wrote: Mon Nov 11, 2024 10:10 am You need to look where it is running lean and make adjustments to those areas of the table where it is lean.
do I adjust it by 10% increases and go from there or?

Re: P0171 code

Posted: Thu Mar 13, 2025 9:01 am
by Spunkster
You can try it and see what effect it has.

Re: P0171 code

Posted: Wed Apr 16, 2025 8:16 pm
by CalibratEd
Adjust the AFM so that it does not run lean. Is there any reason the fuel trim min and max were adjusted? With value so low, you are more likely to get a lean code if your fuel trims are not spot on.

- Ed

Re: P0171 code

Posted: Mon Jul 28, 2025 10:35 pm
by Od1n
CalibratEd wrote: Wed Apr 16, 2025 8:16 pm Adjust the AFM so that it does not run lean. Is there any reason the fuel trim min and max were adjusted? With value so low, you are more likely to get a lean code if your fuel trims are not spot on.

- Ed
No idea about the fuel trim values. Bought the car already tuned from a reputable workshop but a few days later error code showed up. Was ok during the test drive. Would really appreciate it if you have any recommendations on what to change it to!