More car detail would help, i.e. year, 4 or 6, miles, etc.
I'm assuming you are referring to a fuel injection and fuel induction service. This wouldn't be a service a dealer or quick lube place is insisting upon would it? Unless a car has high mile and is not running properly, the detergents in the gas should keep the fuel system clean and such services unnecessary.
A fuel injection service would consist of running cleaner through the fuel lines and injectors with the engine running. Induction cleaning consisting of removing the air cleaner and ductwork and spraying the throttle body with a cleaner to remove the carbon from the intake.
My trusted mechanic uses the Motorvac System. The service (~$110) includes both fuel injection and induction cleaning.
I've have it done once on my older cars with higher mileage. After that, I add a bottle of Chevron Techron or Seafoam once a year in the gas tank as preventive maintenance. Once a year, I pull off the air cleaner and clean the throttle body with a spray can of throttle body/MAP sensor safe cleaner. Do not use carburetor cleaner it will damage the coatings on the throttle body and MAP sensor.