Commanded AF Ratio changes at Idle in gear

[Rickgypsum]

2015 Camaro L99 Auto Trans E38 ECM
Did a DOD delete and installed stock LS3 cam. GM 12623063

MAF and VE table fairly dialed in and runs great with one exception. When coming to a stop in gear for the first ten seconds it idles at 14.6 AF and is smooth. After about ten seconds the ECM commands 12.77 AFR and is in open loop. Then about five seconds later it goes to 16.14 AFR open loop and in another five seconds it goes back to 14.7 closed loop. See attached log file at the 19:32:20 mark. Calibration file also available.

This only happens at idle and in gear. If I shift into neutral within the first ten seconds, AFR stays normal.

Thanks people!

[blindsquirrel]

Sounds like the Catalyst Test. Does it do it every single time you come to a stop, or only once per drive?

[Rickgypsum]

Does it all the time after normal temp. I'll disable the cat overtemp and see if it stops. Haven't tried that yet. Thanks

[blindsquirrel]

Does it still have cats & downstream sensors? If so you shouldn't turn that stuff off.

The catalyst test is not the same as catalyst overtemp. Cat test enable/disable is not in recent versions of the software.

[Rickgypsum]

Yes, it still has the cats. Currently and temporarily has a WB in place of the downstream sensor but was doing this before I installed the WB. Disabled the cat over temp long enough to find out that it did not change anything. So is there a software version out there that allows access?

In a unrelate matter found version 4.10.7 that allowed me to adjust the Virtual Torque of which the current software doesn't. It fixed the bumpy downshift it always had when coasting to a stop, firmed-up the upshift a bit more and reduced the amount of gas pedal travel needed to get the same throttle opening. I believe HP Tuner software is the first one I'm aware of that removes features instead of adding more. Or is that the reason they have another upcharge to "build your own PID,s" thing?

[blindsquirrel]

Does it run bad when it does this? Or is it something you'd never know about if you didn't have logs to study closely? If it's just a data thing and not a running thing, you should not try to fix something that is intended behavior.

[Rickgypsum]

Sorry for the delay. Busy week.
Idle is not really bad but you can feel when it changes AF ratio. Especially when it goes from rich to lean.
What doesn't make sense is this only happens when the transmission is in drive. Shift into neutral within the first few seconds after a stop and it never happens.

[Rickgypsum]

Problem solved. Bad or something not right with the fuel injectors. None were dead but doing an injector cancel test, sometimes, it was a barely noticeable change on a couple cylinders. But not always and not on the same cylinders either.
Bit the bullet and bought another complete set and the issues are gone.