MAF DIALED IN PERFECT, Out of nowhere at idle, LTFT GOes RIch, O2 Voltage goes Lean

[LSandlteditor]

Fuel trims are all dialed in on my 6.2L stage 2 TSP Cammed Avalanche. Everything looks perfect, but out of nowhere, LTFT Goes Super rich, like -18, however o2 Voltage drops, and my wideband reads lean, for about a minute, then everything gets back to normal. Ive been chasing my tail trying to figure out why its doing this. I Cant figure it out. I will post the tune, and the Scan file below. I am seriously getting pissed off. DFCO is disabled through, dynamic airflow set to 200, 150, running MAF ONLY tuning MAF only at the moment.

Stage 2 texas speed LS3 Cam
6.2L Avalanche WIth 6l80e.

Please if anyone has any idea what can cause this, let me know. I just put brand new o2 Sensors in as well. Fuel trims start to go rich at the 8:08 Mark. Please let me know what is causing this?

WIerd Idle RIch.hpl
6.2l Avalanche TSP Cam CIrcle D 3200 Stall 6l80 TEO4idle.hpt

[LSandlteditor]

Anyone?

[RobZL1]

Got headers? Haven't looked at the logs, but based on what you're saying it's happening because the o2's need to be forced to oscillate more at idle.

[2xLS1]

Can't look at tune. Is it Flex Fuel? Still enabled? If it is look at the commanded A/F and see if it matches alcohol content.

[LSandlteditor]

It has longtubes no cats.

[LSandlteditor]

Flex fuel is enabled and I have a sensor on the rail. It is commanding Properly for 9.0 percent alcohol which is 14.1

[RobZL1]

Quick thing to try to either confirm or eliminate as the problem- drop your integral delay and/or increase your proportional gain in the lower 2-3 airflow ranges to see if it wakes up the O2's. I'd bet that's your problem.

[LSandlteditor]

Exactly which tables is it bro? Thank you

[RobZL1]

Everything you need to know about o2 sensor feedback tuning is in here:
https://forum.hptuners.com/showthrea...Headers/page11
Check the picture here in page 11 to see all of the tables we're looking at.
Specifically, change the values in the first couple of cells in tables 12470 and 12480.

[LSandlteditor]

So I played with the Integral and proportional Settings a bit, and it still does it. Can somebody please look at my scan file and see what im talking about. Go to the time frame of 08:08:58 Until 08:09:12 and watch what it does after i came to a red light to idle. Just observe how my wideband goes lean, LTFT goes rich, and The car chops really hard at that point. PLEASE somebody look at the scan file and let me know why this is happening....because of this stupid issue, its hard for me to accurately dial in the maf. I feel like it happens more as im coasting to a stop and then i Idle at a light.

11 Chevy Avalanche TSP 229-244 3200 Circle D Bolt-Ons 6.2 Swap ACE9.hpt

WIerd Idle RIch.hpl

Please guys...id really appreciate this.

[FASSTRUK]

Are the cat tests still active?

[LSandlteditor]

No they are not.

[LSandlteditor]

Are the cat tests still active?

No, They are not.

[sevinn]

Keep in mind that raw fuel will not be read by o2 sensors or your wideband and could very well show full lean when there is raw fuel in the exhaust. How is the smell? Have you tried removing 15-20% in that low area of the maf where you are experiencing this?

[LSandlteditor]

Its 12 degrees overlap on the cam, I am suspecting DFCo messing with the way the trims look. Maybe I can play with those settings and mess with the o2 Integral and proportional