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 00-06 Audi A4 /01-06 Audi TT /01-05 VW Beetle /01-06 VW Golf /01-05 VW Jetta/01-05 VW Passat/Fits 1.8T

