C6 LS3 Halltech MF108 causing havoc -- need desparate help

[[email protected]]

I swapped Airaid CAI with Halltech MF108 today. Car was running pretty good before but after installing Halltech MF 108 everything has gone haywire. Running in MAF only mode, its reading insanely lean. Idle surging issues, surging issues while coming to a stop.
Also car died while turning left from the signal. The log shows RPM dropped to zero.

After couple of logs and because of surging issues, changed idle airflow, changed etc scalar area, trying to dial in MAF. But nothings helping.

Also second and third gear as i start pressing gas it seems like around 2650 rpms car is trying to apply brakes as if trying to limit torque, not sure how to put it in words but unless I change into next gear car runs really weird.

In need of help to understand whats going wrong

2009 C6 ls3
Mods list:
Halltech MF108 - moved from Airaid to Halltech
FAST 102
NW 103
ARH 1 7/8 long tube headers with catted x pipe
Billy Boat exhaust
Monster twin disc clutch

Tune and logs attached:

[kevin87turbot]

I swapped Airaid CAI with Halltech MF108 today. Car was running pretty good before but after installing Halltech MF 108 everything has gone haywire. Running in MAF only mode, its reading insanely lean. Idle surging issues, surging issues while coming to a stop.
Also car died while turning left from the signal. The log shows RPM dropped to zero.

After couple of logs and because of surging issues, changed idle airflow, changed etc scalar area, trying to dial in MAF. But nothings helping.

Also second and third gear as i start pressing gas it seems like around 2650 rpms car is trying to apply brakes as if trying to limit torque, not sure how to put it in words but unless I change into next gear car runs really weird.

In need of help to understand whats going wrong

2009 C6 ls3
Mods list:
Halltech MF108 - moved from Airaid to Halltech
FAST 102
NW 103
ARH 1 7/8 long tube headers with catted x pipe
Billy Boat exhaust
Monster twin disc clutch

Tune and logs attached:

It's actually not idling at a lean A/F ratio. It's idling around 900mV on the narrow bands. That's pretty rich. The wide band appears to show that it's a little rich at idle as well. It's set to stay open loop. I suppose you knew that already.

[[email protected]]

Thank you @kevin87turbot for the reply.
I am trying to keep o2s and LTFTs out of equation and trying to dial in MAF, hence running MAF only. My understanding is for that you need to be in open loop.
I see now that its idling around 900mv. Any suggestions on that? I will try to reduce idle Airflow Final Minimum tomorrow and see if its idles fine. Trying to find if there is any thread on MF 108 from Halltech and see if there is any need to rescale MAF.

[[email protected]]

Also looking for suggestion on why car decided to die. If you look at the log at 13min you can see RPM dropped to zero, oil pressure dropped, throttle % dropped to zero. I had to start the car again.
I also see Throttle control source went from IDLE to MinPos. Trying to do some research on that as well.
Any help on this issue would be really appreciated.

[Proxses]

It keeps tripping the Low MAF fail frequency. Lower this value to start.

[[email protected]]

Thank you Proxses. I did see that today while going over logs. The low MAF fail frequency is set to 1126HZ but its failing MAF at 1148HZ itself.
Are you recommending to lower this low MAF frequency? I can try to lower it and see what readings I get.
Also I am trying to understand why my O2 bank readings are completely off. Any help there would be appreciated.

[Proxses]

I'm seeing 800Hz from the MAF at various times. It's only under decel, which is why you have a difficult time transitioning into idle. A larger MAF will shift the whole frequency chart downward, as it is sampling a smaller percentage of the incoming air.
I also don't see any issues with the narrow bands. They are mimicking the wideband, as they should.
Try using STFT to tune in the MAF at idle and low flow zones. You should be going back to closed loop at some point, and they will dictate what the car wants to see.

[[email protected]]

Thank you once again. I did lower the MAF fail frequency. Car is not stalling. I decide to dial in vve first. Got it dialed in(thats what I think) and moved back to MAF. Tried to tune MAF with wideband for now. My problem is in the lower areas and when I let go of pedal. As soon as let go of pedal or even try to keep accelerator at constant position, the car is trying to stall. Its not actually stalling but jerks a lot. I have to press in the clutch in to make it decel better.
Trying to understand logs better to understand why its trying to stall when I let go of pedal.

Here are couple of logs attached for reference
2009_c6_step_9_Jun_24.hpl
2009_c6_step_9_Jun_24.hpt
2009_c6_step_8_Jun_24.hpl

[[email protected]]

So I did another change today to see if the jerk issues get reduced. I added 3 deg to Idle Base spark and coastdown as I saw spark literally going in -ve during decel. Also added 1 g/s to the base running airflow.
This has significantly reduced the jerks I was getting. But I am still having issue dialing in MAF especially in the lower frequency ranges.
What I am trying to understand is during decel why MAF goes lean even though Throttle control source is IDLE. If I richen it and start the car i smell gas and see log showing pretty rich.
I think I need to turn off CFCO or something else that will let me dial in MAF in lower frequencies. Need guidance on this part. Attached is the new tune file and logs.
2009_c6_step_10_Jun_24.hpl
2009_c6_step_9_Jun_24.hpl
2009_c6_step_10_Jun_25.hpt

[[email protected]]

Turned on NBs and tried to dial in MAF again today. Tried with filters to filter out possible decel data. Still having issues dialing in lower MAF frequencies.
Also bucking became worse and car again stalled today on decel. Bucking on decel really bad. trying to understand whether I should look into idle right away or should I still work on dialing in ve and maf.
As mentioned in earlier thread I did try to dial in VE and now back to MAF.

Any help here would be greatly appreciated.

Please find attached latest logs and tune.

2009_c6_step_19_Jun_26.hpt
2009_c6_step_19_Jun_26.hpl
2009_c6_step_18_Jun_26.hpl