What could cause all four p0101,2,3,4 misfire codes and the p0171 all at once?

This is indicative of a MAF sensor or other componet(s) that has influence on all cylinders, possible fuel delivery, fuel filter/fouled injectors issue... you need a diagnostic flow chart for testing or a good repair manual ... for a fee > www.alldatadiy.com Maybe a good Volvo tech!!.. To many possibilities for guessing and throwing parts at it!

i would check for vaccum hose leaks first,before you put more money in it.sometimes a vaccum leak will throw false codes like you listed.i had that problem once on my f150,skipping,shaking,not idle.i checked for codes and had 9 codes.i lift the hood and started truck and heard a hissing,sucking sound and found it.1 vaccum hose on pcv valve split and collasped,replaced hose and cleared codes and ran like a top.vaccum hose is cheap.check them and let me know what you find.