I'm going to guess that you used some poor quality gasoline during your trip. These engines and especially the highly tuned M are sensitive to gas quality and additives. Since the fuel pump was replaced, I'm guessing the dealer found some codes associated with fuel delivery. It may not have been the pump but he changed it anyway. I recommend you only use premium gas from reputable places.

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Current:
2017 640Xi Convertible
2011 Acura MDX
2018 Santa Fe

Past:
2013 Honda Accord
2008 Acura TL Tech.------2004 BMW X5 4.8is----2004 Acura MDX Tech
1994 BMW 525i.----------1994 Lexus 300 GS.----1994 Acura Legend GS
1991 Acura Legend LS.----1991 Honda Accord.----1991 300ZX twin turbo
1996 Buick Regal GS.-----1984 300Z 50th anniv.--2002 BMW X5
1982 280Z