Is there a parameter that specifies the position of the Oxygen sensor? E38

[swingtan]

You can increase the time it takes to go closed loop and there is another parameter for temp for heater (forget the name off the top of my head). These two changes help dramatically

There are other things to consider that Fords have control of including HEGO tip temp change, exhaust flanges will change temp as well, etc. maybe this is available in GM

That will only change when CL mode will begin, it will not change the "reaction time" of the ECM from a fueling adjustment to when the O2 sensor sees the change.

CL Idle mode does however seem to meet some of the needed criteria. If you look at the images I posted earlier, you can see the CL Idle mode does not command as big a swing in AFR's as normal CL mode does. I've played with the settings and had "CL Idle" mode active at normal cruise speeds to prove it can be done, and it works OK. I think it might mess with LTFT's though ( only an assumption at this stage ). I've also played with dynamics, timing corrections and throttle air flow corrections and have a rock solid idle at 650 RPM (M6) with the 220/224@114 cam. In fact it's probably smoother on the logs traces than the stock idle was and does not hunt with the CL cycling.

Simon.

[etmotorsports]

stock2012Vettels3dry.ctz

STockLS3DrySump_01.efi

I tuned a 2012 corvette with long tubes the only problem the headers seam to cause is at a cruise here is a datalog of the run on the dyno, i cruise for a little while at 1800-2000 rpms and you could feel a surge on the street you don't notice it as much but sometimes it is there. I am sure it is form the stft adjustment. I thought it was from the o2 being farther from the cylinder head but if you look at the tune in the ve table it is on the border of a zone i believe and you get a large change from -14 to 0 or 4 % i think that could be the issue will try to tweek that later. The idle seems to have no issues but it is a stock cam.

[swingtan]

Easy test.... just force it into OL mode and retest. I bet the light surge is still there even with the O2's turned off. Let me know if that's the case.

Simon

[etmotorsports]

Swingtan

It will be a week or so before i can drive the car again and that will be at the track so i will not be able to feel it there. If the surge is still there what would that mean? I can't think of what it would be.

[swingtan]

If it's not fuel trims, I'd be looking at dynamics or idle integral steps. Try dropping {B1844} (coast down ) by 50% for starters. You will need to get your min idle air correct though, or you may end up with a hanging idle.

Simon.