Hi,

Complete noob here...

Been trying to dial in my new ID1000 injectors with wideband ECU (1.8t Engine) and have noticed that my target lambda randomly falls to 0.95 instead of 1 on idle. I can't for the life of me work out the reason for that.
Car is stationary, no detected misfires so what gives?
Car is APX engine recently converted to wideband, no EGT, no secondary o2, no cats, no evap, no n249 (previous owner removed), no SAI.

Is there a map/variable to turn off this "feature"? I followed the s4 wiki to disable everything related to rear CAT and rear O2.
The log clearly lamfa_w as 0.95 at some points during idle (for prolonged periods).
I've attached the final part of the log which shows this (LTFT disabled for now).

The file in the xdf thread is stock *as far as I know*, however I downloaded it from this forum some time ago.
In the file I run CLRSKA is set to 0 along with all the other changes defined in s4 wiki (I double checked every single variable this morning).
The car is still setting lamfa_w to 0.95 on idle, after driving also.
Any idea where I should look (SAI? rear o2? cat model?). What can cause lamfa_w to change other than driver input?

That's very helpful, thanks.

Looks like lamfawkr_w is based on ignition retard, which I have logged and it is 0 across all cylinders, so I can cross that off.
Lamfwl_w is warm up enrichment so this shouldn't be active (and the log shows stable coolant temperature signal).

This leaves Lamrlmin, which is "Target lambda control to improve the combustion efficiency at lower relative loads" according to the wiki on here.
I have checked the definitions in the OLS and sure enough LAMRLMN variable is 0.9531, which matches my log. There is also a map that triggers it, which is RLLAMMN, I think the values are % load and the first entry 16.5; my log shows that the load dips just below that.The Xaxis is RPM first entry is 1480, so looks like all conditions are satisfied.
So I believe I found the map responsible, however, I don't understand whether this is normal behaviour or my APX MAF values/other changed maps are causing this. I can code it out, but should I?

Can anyone confirm what the standard idle load should be on a 1.8t? Should combustion efficiency enrichment be triggered on idle?

With my ID1000 injectors on 1.8t engine, my krkte is currently 0.0331  based on a calculated starting value of around 0.032 and adjustment using WOT logging. Lambda adaptation is not far off on both WOT and idle with TVUB values 2.7, 1.77, 1.34, 1.09, 0.9 based on starting values from injector spec sheet and adjustment using idle trims.

The MAF values I have directly copied from the APX file (as the MAF is stock APX), the values were are approximately 5% higher than stock values at lower voltages.
My MAF reading at idle is around 2-2.5 g/s.

In any case, I have set LAMRLMN to 1 to check what happens and indeed the requested idle lambda when warm now stays at 1.
However, my misfire counter started to increment, though I couldn't feel the car misfiring (and the RPM is quite steady) so looks like I either have to increase RLSALULL, or increase KFKHFM in the load areas to increase calculated load (if my understanding of load calculation is correct).

I have attached the ps_w vs actual log extract from my commute this morning.
I'm still a new to this, so not sure what it should look like.
Should ps_w follow the boost curve exactly? Because it looks correct at the top end but quite far off during boost building. Should I bump krkte AND MLHFM but then reduce KFKHFM at the top end?

The car is running hybrid turbo at 22psi, 8.5:1 JE pistons, forged rods, 80mm tip, K&N cone filter and HG FMIC.
Thanks for all the help so far.

Are the KFKHFM values from the APX file as well?