that is a great point since optimal L.TRIMs never go above or below 5%. and as long as you leave S.TRIM to do it's thing, the AFRs should continue to get corrected when needed. Once you see a definite drift in S.TRIM you know you have a problem like one you mentioned above. I wonder if it's worth limited S.TRIM to +/-15%?gtfrede07 wrote: ↑Tue Sep 17, 2019 8:17 amYes. Proceed the same way. When happy with the s trim; re-enable l trim. I am personally going to limit mine to 5% +/-. All this would help with is the tune remaining close to optimal should the oxygen sensor start failing or if an exhaust leak would develop later on. Would not let the trims get completely out of whack based on false readings later in the cars life.
I am going to try your method this weekend and see what I find.