93 Octane

Noticed check engine light flashing for a second during the pull but all gauges looked fine during the pull. Not sure what that was about. Also has current dtc 20A503 and 11B210

Looking for anything out of the ordinary, focused on timing and fueling.

One normal driving with some stuttering. May been a little cold but temps shown it was ok. Other pulls 3-4 may have stopped log a bit quick on one.

Forget the circumstance but car was driving great. Driving home from work, let the car warm up, plenty of gas

Went to get tires. Engine started to stumble and AFR went to 0. Dead Sensor. Replaced sensor, AFR readings are back but car runs like junk and will stall and at idle with AFRs all over the place. Did a quick check on clamps and other things and all seems tight and connected.