I replaced the front O2 sensors on my 2010 and it started having idling issues when started.
I went to the dealer for the sensors. They said the ones for my car were obsoleted and had replacement sensors were available.
Once I installed them in my long tube headers, the car would fire up fine, but then the car would start running super rich and the idle would stumble. After 15-20 seconds, the idle would clear up and the car would run fine.
It didn't matter if it was the first start of the day or after stopping for fuel on a road trip, the car would start fine, then run badly, then clear up and run fine.
My tuner said my short term fuel trims were not reading properly (I may not be using the correct terminology here)
I bought some new O2 extenders and replaced them, but it did not help. ( they are fairly cheap so no big loss)
Thankfully, I am somewhat of a hoarder, so I still had my old O2 sensors. I put them back in and the warmup idling issue was gone.
I made a video of the car idling with the old sensors in to show that it runs fine. Then i switch to the replacement sensors and show how it runs bad.
Hopefully, it will help someone else when they go to get new O2 sensors.