How do I change the oxygen sensor on 2006 Honda CRV

Well it depends on a crv if you look under your car from the drivers side to the area of the second row of seats you will see the catalytic converter. Connected in the cat you will see 2 sensors. They are about the size of spark plugs with wires coming out the back.

The one on the left is bank one sensor one upstream which is actually an A/F sensor. It has a male 4 pin/4wire plug. the wire connected will be going up towards the engine.

The one on the right is an O2 sensor bank one sensor two downstream. It has a female 4 hole/4 wire plug.

Unscrew the sensor and unplug from harness then install new one by reversal.