I just bought a 2011 xc90 with CEL code P0420. Is there a Volvo scanner available that will tell me specifically what the problem is? O2 sensor, cat convert, exhaust, … or do I have to take it in to have all these components checked to pinpoint the problem?
Thank you!

3.2L 6 cyl FWD

 

The best scan tool is the Volvo factory tool VIDA. You can purchase a subscription or you can find a free version of the stolen and hacked version of VIDA 2014d easily on the internet. You will need a DICE unit to interface with the car, A clone dice unit might cost $85.

No software/hardware will tell you specifically what the problem is - Vida will give you suggestions and possibilities (more than any other scan tool I have seen) but it is still up to the brain of the user to follow the clues as to what is causing the codes to be stored.

A Po420 code relates to cat converter efficiency. The front oxygen sensor measures free oxygen before the converter, the rear after the convertor. In theory the convertor is supposed to convert CO, HC and O2 - into CO2 and H2O. If there is too much oxygen left over after that process - you can get a 420 code. So that code is not as simple to solve as others. Especially since that part of the self test - (to make sure what you did solved the problem, the portion of the drive cycle that tests the cat) is near the end of the drive cycle and can take quite a while to get to - if you don't follow the driving pattern to finish the test as quickly as possible. (back to the brain/knowledge of the user) Some have used O2 extenders to put the rear sensor out of the exhaust stream to solve that code - that can be an inexpensive fix. (although not legal to circumvent an emission device, but people do it all the time)

My first step would be to note and erase the code/s and see how long it takes for them to come back, since you "have just purchased" this car and have no history.

 

Thanks for the info. I’ll look into getting a VIDA.