For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

California Proposition 65 WarningInstrument Panel Compartment Replacement
Instrument Panel Compartment Replacement
Callout
Component Name
Preliminary Procedure
Remove the right instrument panel upper trim panel. Refer to Instrument
Panel Upper Trim Panel Replacement - Right Side.
...
Catalytic Converter Replacement (LUV)
Removal Procedure
Warning: Refer to Exhaust Service Warning.
Warning: Refer to Protective Goggles and Glove Warning.
Remove the exhaust manifold heat shield. Refer to Exhaust Manifold Heat
Shield Replacement.
Remove the catalytic converter heated oxygen senso ...
Engine Front Cover with Oil Pump Replacement
Removal Procedure
Disconnect the battery negative cable. Refer to Battery Negative Cable
Disconnection and Connection.
Set the engine to TDC. Refer to Camshaft Timing Chain Inspection.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Remove ...