2017 XC90 2.0T diagnosed as Lean Bank 1 so dealer said I should replace Front o2 sensor. Am I correct in thinking that a 2.0 4 cylinder engine has only 1 bank and that the location of the sensor should just be the only one before the catalyst?

Thanks!

 

Yes only 1 bank, but I would erase the code, turning off the CEL and make sure there is not an air leak or whatever else VIDA recommends as a solution. O2 sensors are very robust and rarely need replacement. Dealers techs usually work on commission - and service advisors usually partially on commission - (so they get paid on both the parts and labor they sell) - so see what happens if it is erased - how long does it take to come back? Is there anything else that could be causing a lean condition?

Or spend whatever the dealer suggests and believe that it will be fixed.

 

Thanks for the reply, I believe the dealer erased the code and then was back on the next day, then off again for a few days and on again. I cleaned the MAF and it stayed on. Took it to a private shop and they say the same thing the dealer did, I may have made an error in telling them what the dealer said though. I don't see any physical signs that something else could be wrong, no weird noises either. This all started about a week after an oil change so don't know if something happened there, but can't imagine what that would affect. I agree it is weird for an oxygen sensor to go that quickly. Any other ideas?

 

Then have the private shop do what they think will fix it - (not what you told them!) As long as they will refund your money and put your old part back if it does not fix it. I owned a Volvo shop for 38 years - and believe that the right diagnosis is worth paying for - and the wrong diagnosis the customer should not pay for.

 

Sounds like a good idea. I forgot to mention that I have a tiny lower radiator hose leak, could that and the error be connected? Was going to replace that myself, but noticed I need to use the vacuum tool to re-fill coolant and I don’t have a compressor. Should I have the shop fix that first and see if it takes care of the problem?

Thanks!

 

Or should I just have them do both at the same time?

Thanks

 

I just talked to the private shop. They say they are 99% sure of the diagnosis being the O2 sensor, but if there were another issue after that is taken care of then they would not swap the parts and we’d still be charged. If that is the case then it sounds like I might as well just do the sensor myself right? Then have them look at it if the CEL doesn’t go away?

Also if I do a coolant flush is it safe to fill coolant without a vacuum tool? I don’t have an air compressor, that’s why I ask.

Thanks

 

Update?