Toyota Repair: Alternating 0125 & 1130 Codes, toyota solara, exhaust manifold

Question
QUESTION: I get these codes coming up. I can check it one time and get 0125, clear it and within 2/3 Miles the light comes back on. I hook up the scanner and the code changes to 1130. Can you tell me which Sensor to change and it's position on the motor? Thank You

ANSWER: Yes I can but I will need to know what year/model it is and what engine it has.

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QUESTION: Hello,
    I have a 2000 Toyota Solara SE V6 3 liter Automatic 1MZ-FE Calif. 123,000 miles.
    Thank you.

Answer
The P1130 code indicates a failure of the A/F sensor bank one sensor one, it's located in the exhaust manifold near the radiator, replace this one to solve this problem, the PO125 code is a secondary code and can be ignored because it will be fixed after replacing the sensor.