Fuel trim hot weather

[theblackdogman]

2019 HB sport CVT KTuner/TSP1. I have no other mods. Not even air filter. Fuels trims were perfect until 2 days ago. The 95 degree weather came (Florida) and all of a sudden I’m at -13 even after 30 min of light driving. Does temp affect trims?

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[fenix-silver]

2019 HB sport CVT KTuner/TSP1. I have no other mods. Not even air filter. Fuels trims were perfect until 2 days ago. The 95 degree weather came (Florida) and all of a sudden I’m at -13 even after 30 min of light driving. Does temp affect trims?

I assume you are referring to the LTFT and not STFT? Last summer my Si seemed to hover around -7 when it was hot and humid, but -13 is likely bordering on a bit extreme. (Very possible that the non-Si 1.5t is more sensitive to heat/humidity than the Si engine). As long as it doesn't drop much more, you should be fine as it's just the ECU doing it's job, but certainly keep an eye on it. This seems pretty common with these engines. I'd rather have the ECU pulling fuel than adding it since running rich is typically safer than lean.

 

[Static_Awesome]

2019 HB sport CVT KTuner/TSP1. I have no other mods. Not even air filter. Fuels trims were perfect until 2 days ago. The 95 degree weather came (Florida) and all of a sudden I’m at -13 even after 30 min of light driving. Does temp affect trims?

2nd-ing serious issue. What part of Florida are you in, I'd be happy to help chase this down with you if you're close. I'm near Jacksonville myself.

 

[NoelPR]

It happens when the temperature compensation tables aren’t setup properly.

Hot and humid means less oxygen in the air. Ecu will reduce fuel to make the target AFR. Showing negatives.

 

[Woduddl0303]

Any update? My LTFT was around -14 with TSP1 and PRL cobra street intake. Turns out the filter was over oiled from factory. I cleaned and reoiled it myself and now it's at -1

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