Re: 02 oxygen sensor diagram/location P0133 P0420
Sorry for the late reply....
That's entirely up to you. Personally, I'd replace the faulty one and be done with it if/untill another decides to fail. Not sure which brand sensor you bought, but I tend to stay away from Bosch sensors. From personal experience, the sensor tips tend to be tuned to retard the sensors performance.
2014 WK2 Overland - Billet Silver