How do i fix my 2001 cadillac catera idle problem. ive tried fuel injector cleaner, changed the spark plugs, and o2 sensors, but it still idles rough and im throwing these codes. bad o2 sensor bank 1 sensor 1, and cyl. 1-3-5 misfire.

The problems you are describing indicate to me that you likely need to replace the coil pack that runs from the spark plugs ,and the plug wires end up at it.It also may be the spark plug wires,get a water bottle and spray the wires after dark and if you get a light show from them then replace them,if not,replace the coil pack.

Swap the 2-4-6 coil pack with the 1-3-5. On the 01, they are symmetrical.
If the codes move to the 246 cylinders, you have found the problem.

I had wandering idle all over the place after the battery was disconnected and had to relearn the idle by leaving the key in the on position for 3 minutes without engine start. Then key off and then engine start.

Later, I had a wandering idle problem solved by new MAF sensor.