Okay, I had the Bank too lean codes in my 2010 XC90 along with the whistling sound. Replaced the PCV Oil trap, reset the code and ran the engine. The whistling stopped and I took it for a test drive only to have the 'Check Engine' Light come on with the same codes given. Am I missing something?

Thanks in Advance.

 

https://volvoforums.com/forum/volvo-...74-help-84730/ might be of some help. The codes indicate there's an intake air leak. this thread talks to one of the possible causes that's related to the PCV.