Did you reset the computer after installing the new MAF? Do you mean Prosport? Not passport. Might need to recalibrate the O2 sensor for it or replace it if it's old.
As for the misfire. Have you checked your plugs and coils? Not that all 4 typically go at once. Crank position sensor can cause misfire codes. And lightened flywheels are notorious for it. Especially if they are combined with a light crank pulley.