What do 02 extenders do?

It is used to monitor the health of the cat. The spacer puts the O2 sensor out of the exhaust flow. This tricks the ECU into thinking that the cat is working when you don’t have one or have a high flow one.

Can you solder an O2 sensor?

They must be crimped on for the O2 sensor to work correctly. For the sensor to work correctly, it must draw clean air down to the sensor through the air gaps in the stranded wire. If you solder the wires, the solder will fill the air gaps in the wire and the sensor will not work correctly.

Is it OK to solder O2 sensor wires?

You should never solder a O2 sensor wire because the sensor “will breathe” through the cable. The acceptable method of splicing or repairing O2 wiring is with crimp connectors.