55577403 GM Fuel injector

What is this part?

The GM fuel injector 55577403 is a genuine OEM engine fuel system component responsible for precisely delivering fuel into the engine for combustion.

What does it do?

This OEM fuel injector meters and sprays fuel into the intake port or directly into the combustion chamber at the correct timing, pressure, and spray pattern. Accurate fuel delivery ensures efficient combustion, optimal engine performance, fuel economy, and emissions control. A genuine GM fuel injector is manufactured to factory specifications to provide correct flow rate, atomization, response time, and durability under high pressure and temperature.

When to replace

The GM fuel injector 55577403 should be replaced if there are symptoms such as misfires, rough idle, hard starting, poor acceleration, increased fuel consumption, fuel leakage, or diagnostic fault codes related to injector performance. A faulty injector can lead to incomplete combustion, engine damage, or emissions failures. Installing a genuine OEM fuel injector restores precise fuel delivery and reliable engine operation.

Compatibility

The genuine GM fuel injector 55577403 is compatible with selected GM engines and fuel systems. Compatibility depends on engine type (gasoline or diesel), injection system (port injection, direct injection, common rail), operating pressure, and model year. Always verify the part number 55577403 before purchase to ensure correct fitment.

Installation: DIY or service?

Installation of the genuine OEM GM fuel injector 55577403 varies by engine design. While some port injectors may be replaced by experienced DIY users, many applications—especially direct injection and diesel systems—require specialized tools, torque procedures, sealing replacement, and calibration. Professional installation is recommended to ensure proper sealing, performance, and safety.