Restore accurate fuel metering, stable rail pressure control, and dependable performance on your 2004.5-2005 GM 6.6L Duramax LLY with this genuine Bosch fuel metering unit. This direct-replacement metering unit helps correct fuel pressure concerns such as hard starting, unstable rail pressure, poor throttle response, fuel pressure codes, and drivability issues. Bosch: 1465ZS0058 Installation Note: Verify related pump, rail, and fuel system diagnostics before installation. Fitment Note: Verify build date, VIN, engine application, emissions package, and existing part number before ordering.