Could be the oxy sensors or cats.
But don't panic. I know thet cats are quite expensive.
Usually the oxy sensors get quite 'lazy' after a certain time and it is usually recommended to change them at around 60 k miles.
And also do not warm up the car at standstill in idle. Not good for the engine. Immy when the engine is on, start driving in a range between 2000-2.500 RPM if possible.
The auto trans is even laid out that it switches later into the next higher gear when engine is cold. Advantage, engine gets warmer faster, oil circulation and pressure inside the engine is faster with medium range RPM instead of idle, cats get warmed up faster.
The oxy sensors by the way can send whatever data to the ECU during the first 90 seconds or so, that does not matter. The ECU is calculating at that time with a set value with richer fuel/air ratio, not the actual data reported by the oxy sensors.
Maybe your cats were not just heated up to normal operating temperature. Drive a little bit longer that all gets to operating temp, and then check again.