My mpg dropped quite recently and gave me a P2A03 Code. I went to look at my O2 sensor readings and found that both Sensor 1 for bank 1 and 2 are reading 2.2+ while idle and 3+ right as i turn the car off. Wtf am I dealing with as i just replaced one of the sensors yesterday and it still reads this voltage. Both downstream sensors read what they're supposed to, its just the upstreams.