Sienna 2000 - Code P1130

[Hola]

The engine light came on and the code is P1130, according to the code reader the problem is the Air fuel sensor, does any one knows where is this located. I am confused too because another description for this code came as

P1130 Toyota A/F Sensor Circuit Range/Performance Malfunction (Bank 1 Sensor 1)

Any ideas?
Thanks,

[sensor555]

I have codes P1130, P1135 and P1153. I wish I could find step-by-step diagrams on how to clean or replace the air fuel sensors.