Just replaced the MAF as the car was throwing out PO102. Still have that code and now many more. PO102, PO101, PO103, PO223, P1224, PO221. What would you all recommend?

 

Did you replace it with an OEM MAF? If you chose an aftermarket MAF that may very well be your problem. If you chose an OEM MAF then it sounds like you have other issues such as connections or a wiring problem somewhere. Or, during your install process you fuxored other things.

What year is your Maxima? This makes a difference because 02 and 03 models are drive by wire and if you removed the throttle body or tweaked it then it could be more problematic.