Q: 2009 Nissan Murano has the P0420 trouble code. It says the normal bank 1 issue, but now it says short to VBAT. What is that and how to fix it?

Hi there. From the description you have provided, for your vehicle’s P0420 trouble code. I suspect the O2 (Oxygen) sensor you replaced has created an additional concern for your vehicle. Either, the O2 sensor is incorrect by application or is wired wrong. The replacement O2 sensor may be faulty, shorted heater circuit in the sensor. Unfortunately, the O2 sensor more than likely will not repair your vehicle’s P0420 code.

This code is an insufficient catalyst efficiency code. Typically, the cause for this code is a catalytic converter no longer performing. It could be, an exhaust leak before the downstream O2 sensor. I recommend having your vehicle’s P0420 trouble code be diagnosed and repaired by a certified technician, such as one from YourMechanic.