Front O2 Sensor Replacement - Cut and Solder the Wires??

I don't see why the wires leading out of the new sensor couldn't be cut and soldered to the old wiring without unplugging the old sensor. That would eliminate the need to dig into the interior of the car to plug in the new sensor.

Any particular reason??

 

But why would you? Seems like it would take less time to remove the 4 screws on the door sill and remove it, unplug the old sensor and plug in the new one. It's a matter of preference I suppose. As long as you got a denso sensor you may do as you wish

Also the rear sensor is the one that has the wires leading into the cab, the front sensor harness ends on the transmission, I have an auto idk if its different with a manual