Volvo Drive-E Front O2 failure
This has been getting to be a very common failure of the Front O2 sensor causing lean codes on these 2.0 T5 and T6 engines (Turbocharged and Super/Turbocharged). The key to getting it to act up is by free-revving the engine for a minute or two and then letting it come back down to idle. When idling again the fuel trims will rise up to 30-50% showing dead lean but the rear o2(s) will spike up to .95-1.0V showing dead rich.
Attached is a screen capture showing the issue.
Hope this helps someone out there!
Thanks for taking the time to post this. Good lookin out!