Fuel According to GM
Apparently, General Motors does not endorse, support or acknowledge the need for fuel injector cleaning as a preventive maintenance procedure. According to GM, fuel injector cleaning is approved only when performed as directed by a published GM driveability or DTC diagnostic service procedure.
By the same token, GM says that due to variation in fuel quality in different areas of the country, the only preventive maintenance currently endorsed by GM is the addition of GM Fuel System Treatment PLUS added to a tank of fuel at each oil change.
The ACDelco part number for a bottle of treatment that treats up to 20 gallons of fuel is 10-3003.