Can hot weather and high humility cause high negative long term fuel trim ?

Friction

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I noticed the same thing, I'm all stock with tsp s1 and saw as high as -12% so far this summer. If your knock is fine I think its just compensating for weather like others have said.
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REBELXSi

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Fwiw, I've only ever seen high LTFT numbers in hot weather during traffic.
 

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Fwiw, I've only ever seen high LTFT numbers in hot weather during traffic.
Yea, that -12% was while sitting in a drive thru
 

REBELXSi

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Alex_hockey69

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So I put back my K&n short Ram intake today and with even hotter temperatures outside today and more humidity I was at -3 long term fuel trims max. I did adjust the scaling of the MAP a while ago . So i guess this is telling me that the car stock comes with very Rich fuel trims. After trying the stock intake on and no tune getting -15 LTFT and even on hondata +psi getting about the same with this hot weather
 

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So I put back my K&n short Ram intake today and with even hotter temperatures outside today and more humidity I was at -3 long term fuel trims max. I did adjust the scaling of the MAP a while ago . So i guess this is telling me that the car stock comes with very Rich fuel trims. After trying the stock intake on and no tune getting -15 LTFT and even on hondata +psi getting about the same with this hot weather
If you adjusted the MAF when you had the Short Ram on before, then Yes - stick with that. Otherwise the readings will be off any other way.
 
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Alex_hockey69

Alex_hockey69

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If you adjusted the MAF when you had the Short Ram on before, then Yes - stick with that. Otherwise the readings will be off any other way.
Weird that there off when the car is completely stock
 

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Weird that there off when the car is completely stock
Right, but your adjustments to the MAF voltage is still the same as if you had the Ram installed right? Different intake s will register differently.
 

alxgravel

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TSP stage 1 map 3
27won intake
27won rmm
77k kilo
Here down in mtl... I'm getting -25 stfb1 on idle and going to do maintenance 1 and 9 ... I tryed stock tune and same thing happen so... I will ask to my adviser to tell to the tech to find what is going on. I'm very lean on idle and on low gaz so maybe injector problem or a leak and I changed my plug last week.
I pmed corey from tsp and they said nothing to help me out. They will fix my ac to ...I'm getting warm air on driver side. Monday I'm going to the dealer and I have full waranty so let see. Will keep you updated to this .

Honda Civic 10th gen Can hot weather and high humility cause high negative long term fuel trim ? Screenshot_20200704-193401_Chrome
 
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Alex_hockey69

Alex_hockey69

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When I return the car to stock just to see what the stock trims are I was getting almost -15 LTFT on a very hot day. Now having put back my K&n short ram and flashed back to hondata +6psi with my scaled MAP adjustment with that I did with my K&N short Ram intake I am getting not more then -3 LTFT. Just saying is this normal that the car stock would have such trims like this . ...
 

alxgravel

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When I return the car to stock just to see what the stock trims are I was getting almost -15 LTFT on a very hot day. Now having put back my K&n short ram and flashed back to hondata +6psi with my scaled MAP adjustment with that I did with my K&N short Ram intake I am getting not more then -3 LTFT. Just saying is this normal that the car stock would have such trims like this . ...
Well I don't know I will tell you more monday after the inspection by the tech.
 

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Run some injector cleaner for the next 2 tanks. Something with PEA in it. Gumout Regane, Royal Purple Max Atomizer, Redline, etc.

My injectors clogged up at 75k kilometers. No amount of injector cleaner would fix my issue.

If the cleaner doesn’t work, they’ll need to be replaced...very $$$. $1250.00 for me plus tax.
 

alxgravel

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Run some injector cleaner for the next 2 tanks. Something with PEA in it. Gumout Regane, Royal Purple Max Atomizer, Redline, etc.

My injectors clogged up at 75k kilometers. No amount of injector cleaner would fix my issue.

If the cleaner doesn’t work, they’ll need to be replaced...very $$$. $1250.00 for me plus tax.
I thinking about an exhaust leak. Sound is more agressif since 5k kilo. My friend is running same setup on his sport and stfbt1 never go above -8.

I know thoses injector are weak but I dont think I need injector cleaner ... Running 94 oct since days 1.

And why the dealer charged you ? They changing it alot on 1.5t not tuned lol.
 
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Chandler92

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I'm on maperformance stage 2 with their intake and tune and I see ltft +5 and stft moves around to +10 and sometimes hits the negatives
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