You sure you have a tbi predator? These don't have a maf sensor, rather use a map sensor for measuring manifold pressure. If tbi you will have a small round flame arrestor sitting where a carb would normally sit. If it has a big aluminum plenum and a throttle body pointing down at the front (or back depending if dd or vd), then it's a 330hp ltr with injector for each cylinder. Take a pic and we can confirm.
There is no 02 sensor so wierd that the code is saying that.
Just Checked online and code 44 is for a bad knock sensor not o2 sensor. If bad, it will reduce the timing and power...
Here's a post including info on the fact it can be bought at a auto parts store since isn't a marine specific part: