A faulty mass air flow (MAF) sensor can cause erratic/rough engine operation and fuel economy issues. Since this sensor measures the actual amount of air entering the motor, when it fails, the engine control module (ECM) takes the wrong information and delivers incorrect volumes of fuel to the cylinders.
Car Problem Reports
Mercedes-Benz CL600 Faulty Mass Air Flow Sensor Causing Erratic Engine Operation and Poor Fuel Economy
Mercedes-Benz CL600 Problem
Visitor, 2002 Mercedes-Benz CL600, 92,000 mi
Faulty mass airflow sensor causes random misfires even after failure and replacement of both coil packs, plugs and boots.