2015 V60, p0042 Heater Control Circuit Bank 1 Sensor 3

[hellarch]

Hi folks,

Recently get a CEL with code p0042, not sure if I need a new o2 sensor. Also confused with the diagram that there are three o2 sensors plugged in the cat, any clues about which one is the sensor three?

https://www.volvopartswebstore.com/show ... veLine=441

PS: I crawled under the car see all three of them are on the top of this weird shaped cat and found they are extremely hard to reach. Any hints of how to get the access to these sensors will be SUPER helpful!

Thanks!