Long Term Fuel Trim

Hello there everybody :D

I have a Question concerning Long Term Fuel Trim. I have a 2018 Ford Focus RS, Downpipe, Exhaust and Airfilter have been done with no Tune. Now just 5 Minutes ago i checked some Values in Forscan and i stumbled over double Digits on one of the 4 Long Term Fuel Trims. I know that if i bring that up in the Dealership they just gonna ask if it has thrown a Code and if i say no they probably gonna say its fine.

My initial Question would be if this should actually be a concern or am i just a bit dramatic? :D

The Car has btw 48800 KM.

I attached a Screenshot to this Post with the Number from Forscan.

Thank you im Advance for any Answers or Ideas.

Greetings :)

It's certainly possible that your exhaust changes have required a 3-10% extra fuel. Assuming that ECU can be flash tuned, you should be able to tune it to remove the long-term trims.

Mh, thanks, so maybe the 200 Cell Cat plus the Exhaust paired with an Eventuri could have that much of a difference?

Wouldnt that be noticable on every Cylinder rather then just one? Considering that one is running at nearly Zero Percent.

And i just remembered, that the Engine has the weird Habit of Injecting even if i lift the Foot off the Acelerator. Picture it as involuntary Cruise Control most noticeable uphill, not enough to accelerate but enough to keep the already gained Speed.

I don't think your LTFT are per cylinder, I suspect they are for a range of RPMs, or perhaps a range of loads. That is typical of some OEM strategies.

Thank you for the Information. :)