Hello,
My '01 3.0 Taurus, has an error code for bank 1 upper o2 sensor. My book doesn't say which is bank one or two.
Is bank one the radiator side or the cabin side?
Please help.
Thanks Much

 

Bank one is next to the firewall. The number 1 sensor is in front of the converter. Also as a rule, number one bank is on the same side of the engine as number 1 cylinder. This is true for all models.

 

Way2old:

How about this method (is this true in all cases?): the front of a transverse-mounted engine is where the serpentine belt is. If looking from the front of the engine, the banks are left to right with bank 1 on the left (near the firewall) and bank 2 on the right (near the radiator).

Some people may not know where their #1 spark plug is, but they can find their serpentine belt.

 

That will work on Ford. Good point.