Hey Scotty My 2007 Nissan Maxima been throwing the same code p2A00 for the past couple months it been like that since I replaced my catalytic converter the code been popping back on, I’ve replaced both 02 sensor with dealer sensor and my mechanic did a smoke test came out no leaks and also reprogram ecu and did a relearn process fuel pressure was good, this has been so annoying anybody ever had this problem and how they fixed it.
Just incase you missed checking all the potential causes -
https://www.engine-codes.com/p2a00_2007_nissan_maxima.html
Just goes to show you the idiots at the dealers don't even know how to fix their own cars. If you near Clarksville I have a machine that analyzes all that stuff I road tested it gives me all the data and his analytical software to find out what is actually wrong I check out cards free if you want to take a trip to Clarksville Tennessee. But I couldn't possibly guess without hooking my computer up
I would definitely would like to have it checked by you
How was the ecm reprogrammed?
Check for shorted or corroded wiring near the sensor. Even though new, as you say, it could be a bad 02 sensor.
I told them that to check wiring, and this is the 2nd 02 sensor they put on it