Maf Sensors Measure the amount of air flowing into a fuel injected engine. If you have a badly running engine and the engine check light reads P0101 then its likely time to replace your Mass Air Flow Sensor. Fit 00-04 Ford E-150/00-04 Ford E-250 /00-03 Ford E-350 /00-03 Ford E-450/02-03 Ford E-550/00-04 Ford EconoLine/00-05 Ford Excursion/99-04 Ford Expedition/02-05 Ford Explorer/99-05 Ford F-150 /2004 Ford F-150 Heritage /1999 Ford F-250 /99-04 Ford F-250 Super Duty /99-04 Ford F-350 Super Duty/99-04 Ford F-450 Super Duty/99-04 Ford F-550 Super Duty/02-04 Ford Mustang /96-99 Ford Taurus/00-01 Jaguar S-Type/03-05 Lincoln Aviator/2002 Lincoln Blackwood /99-04 Lincoln Navigator /03-04 Mercury Marauder/02-05 Mercury Mountaineer /Ford 3.4L, 4.6L, 5.4L/Jaguar 4.0L