motor bogs out uphill on 2002 Volkswagen Beetle TDI

sporadic problem misses under power changed fuel filter twice no help any suggestions

Asked by for the 2002 Volkswagen Beetle TDI
I would check the codes, do you have a Check Engine Light coming on?
I have also replaced a few Mass Air Flow Sensors on the TDI Diesels for this issue, so be mindful of that.