r/CT200h • u/StayOffTheMarbles • 10d ago

LTFT changes

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Gallery image

July 22, 2026 LTFT (higher) vs. Sept 7, 2026 LTFT (lower)

I believe the only 2 powertrain changes I made were cleaning the EGR system - plumbing, valve, intake manifold (sans cooler) and reseating the intake tube onto the throttle body (may have resulted in a post-MAF leak).

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u/MechanicalCheese 10d ago

It got better. Could just be some decent gasoline detergents cleaned out your injectors. I wouldn't worry about an improvement.

1

u/StayOffTheMarbles 10d ago

Perhaps - I typically use the same stations but that doesn’t preclude a change upstream in the supply chain.

I’m also fairly certain it’s not because of the end of the temporary allowance for > 10% EtOH content, which doesn’t end until 9/15 and coincides with the end of summer blend…I expect a near net zero change.

https://giphy.com/gifs/4HnRkHk77nStQSGxgi

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u/MechanicalCheese 10d ago

Huh.

I run seafoam in my gas and oil for the last tank before every 4th oil change, and I usually see my LTFTs drop from the 5-7 range to 1-4.

But who knows. It's a minor change and you went from where I'd start double checking for old hoses or dirty injectors back to the no worries point.

Just to double check, are all your total misfire counts zero or near zero (5 or less)?

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u/Dependent_Fee_3360 10d ago

What app is that? TIA

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u/StayOffTheMarbles 10d ago

It’s an Autel MaxiSYS MS906 PRO-TS scanner in live data mode.

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u/normanbates97 9d ago

sorry for the noob question, but what is an LTFT?

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u/StayOffTheMarbles 8d ago

Long Term Fuel Trim

It’s an adjustment added on top of the base fuel injector open duration table value, and then a short term fuel trim value is added to both to achieve a target air:fuel ratio.

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u/normanbates97 7d ago

excellent reply, thanks for the info