Why is my daughter's beetle short on power? on 2002 Volkswagen Beetle

Struggles to climb hills and high fuel use, lack of power all the time. spark plugs already checked.

Asked by for the 2002 Volkswagen Beetle
2 answers
check codes and advise
you must have a ck eng light on scan codes and post so we can adv. poss mass air flow sensor,very common on these cars