O2 Oxygen Sensor - Honda Acura DIY Replacement

Driving along one day and the Check Engine Light comes on. Low and behold its the P0420 Catalyst System code. Before replacing the catalytic converter, we start with the downstream 02 sensor replacement in which I'll show you how to replace and reset the ECU on a Honda/Acura.

[@excaliburO2]

I know the other code didn't pop up, but you wouldn't change the other O2 bank 2? Before ordering a cat?

[@randomrebuilds]

I believe the code for upstream O2 sensor is P0134.