Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
2002 Ford Escape 3.0 has -20 LTFT and 20 STFT at idle or coasting. More RPM LTFT and STFT go to much smaller numbers but again cancel out. Should I be worried that LTFT and STFT are so high or is it more important that total fuel trim is 0? No DTC, no misfires, no hesitation, no problems. Do I have an issue or zero fuel trim is the bottom line and I should move on?
Right, but I can't get that information for about a week I am traveling.
Just trying to find out what is the most important factor.
Total fuel trim near zero or LTFT near zero?
What do you think is the better direction?
Appreciate your opinion
Total at zero is perfect but STFT is always going to be fluctuating a little. Remember that long term is an adjustable base point set after short term has moved for long enough. LTFT 0/STFT 0. LTFT 0/STFT 10. LTFT 10/STFT0. LTFT 10/STFT 10 LTFT20/STFT0. Hopefully that exaggerated example of an increasing lean condition makes sense. Pretend that is an air leak getting worse over the course of a few days, checked at idle.
