I drove with a bad MAF on my ML for several months, and it gave me occasional starting and poor acceleration issues...ignoring it eventually destroying the fuel pump...while out of town on a holiday weekend. Not including towing 85 miles to the nearest MB dealership, replacing the pump and MAF added $1100 to vacation expenses...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car