Hello, my car has a P2a00 code. It will not go away. So I should start by saying that my car does have headers on them but the code did not come up till after 2 years of owning it. Thing I did : I changed both of the O2 sensors twice with OEM. I have changed out my exhaust pipe that holds my second cat and flex pipe. I cleaned my mass air flow sensor. Nothing gets ride of them. I have a scan tool OBD2 Bluetooth using Torque. Bank 1 sensor 1 says around 0.3 but when on the high way going around 70mph if I let go the gas it jumps to 0.85-0.9. Bank 1 sensor 2 jumps from .085-.9 to almost 0.0. Looking at the graph it looks like it did hit 0 for a tiny bit then jump to 0.85.
My car has 185000 miles.
My car has an automatic transmission.