[5cilinder]

I told you what was left.
If your fuel corrections didnt improve after the injectioncleaner , then you need to do a compression test.
Do that first, a bad compression on some cylinders will affect fuelconsumption

Concerning the MAF the ecu also uses the lamda o2 sensor to check what the rest oxygen is in the exhaust to somewhat double check the airflow..
If there is a leak or a bad MAF the obd2 code air mass performance /out of range or something is thrown with limpmode
Also diesels burns under airexcess (even with egr) so air fuel ratios arent as precise needed as in petrol engines .
You can calibrate the MAF in Vida and check resistance values .
But if its broke you already would have some codes and limping

But your priority is now checking compression..... if thats bad on some cylinders i can give some pointers of how to check if its pistonrings , valve stems valves etc