Ok, If I am not mistaken this is how the o2 sensors run in your vehicle.
First off you only have Bank 1 if it was a V6 you would have a Bank 2.
Anyway here is the numbering, I believe.
Sensor 1 - mounted under intake manifold
Sensor 2 - mounted front exhaust manifold pipe.
Sensor 3 - mounted rear exhaust manifold pipe.
Sensor 4 - mounted near Muffler
Also if you have had any recent work done that may have been near or involved anything near the exhaust. Check the wiring, I recently have this same vehicle with same problem and had had rent work done near the sensors and the wiring was displaced and ended up lying on exhaust pipe and burnt the wires and also blew the fuse.
If you had recent work done and find the wires burnt I would recommend returning to the shop you had the work done at and have them fix it. They should do it free.
Tuesday, August 4th, 2009 AT 9:15 AM