Restore accurate fuel metering, stable rail pressure control, and smooth drivability on your 2001-2004 GM 6.6L Duramax LB7 with this genuine Bosch fuel metering unit. This direct-replacement metering unit helps correct fuel control concerns such as unstable rail pressure, hard starting, fuel pressure codes, poor throttle response, and drivability issues. Bosch: 1465ZS0044 Installation Note: Verify related pump, rail, and fuel system diagnostics before installation. Fitment Note: Verify build date, VIN, engine application, and existing part number before ordering.