Originally Posted by
EagleMark
Mr xtremevette69, I think I found why the Desired AFR is jumping around during warmup! I'm used to it being steady, even when cold it will start at say 10.0 AFR and just steady rise to Desired of 14.13 or if you haven't fixed it 14.73.
Look at "Open Loop AFR Ratio % Change vs. Cooolant Temp" LV8 48,64,80? That is where idle is and look at the changes there. That may be on purpose from GM to rich/lean the AFR along with AIR pump to light off the CAT.
Use the Data Tracing I set up in Spark Advance to watch it.