Too little, Too much, but not just right

 The dreaded check engine light is back on my wife's 2015 Volvo S60.  

The codes it has historically thrown are the P0171 - Bank 1 too lean and P0172 - Bank 1 too Rich.  I am going to begin to tackle this monster with the hope of getting it addressed once and for all.  The primary contenders are:

A vacuum leak - going to smoke test to see if we can find a leak

MAF Sensor - going to take it out and clean it first with some CRC if still an issue will replace

Check the plugs for fouling

Run some injector cleaner through it

if all else fails, consider replacing the O2 sensors

We shall see if we can track down and remedy this problem......stay tuned..