sorry to throw in a question about my 4cyl, '03 Camry but I was confident someone might know the answer. My engine light came on and the computer read: "P0031, H02s, Bank 1 Sensor 1, Heater Circuit Low."

So I replaced the upstream sensor and the check engine light is still there even after disconnecting battery, then I tried clearing it using the diagnostic computer. Any ideas?

Thanks in advance!