The XDP Mass Air Flow (MAF) Sensor XD1054 is a direct-fit replacement for the faulty MAF sensor in your GM 6.6L Duramax LMM. The MAF sensor plays an important role by measuring the amount of air through weight-based voltage changes. This vital information is then transmitted to the PCM/ECM, enabling precise fuel calculations for optimal engine performance. If the original sensor begins to fail, it can result in hard starts, engine surging, stalling, as well as a check engine light. The XD1054 is built to meet the specifications of the original sensor for a direct-fit installation in the stock location. Features: Direct-Fit ReplacementHigh-Quality ConstructionMass Air Flow (MAF) SensorMeasures Incoming Air For Proper Fuel Control