A woman I work with (not terribly mechanically inclined) went to a local chain here in Dallas for an oil change and got talked into her SECOND "fuel injector service" to the tune of $69.95, and her car has a whopping 25K miles on it.
I told her that's the last one she'll be needing until 100K or more, and when it reaches that point, just pour in 2 bottles of Chevron Techron and fill the tank. Also, no 'oil supplements', wiper blades or other **** allowed.
I don't know if this is what is supposed to go on during a 'fuel injector service', but they removed her intake hose and sprayed something into the intake while she sat in the car and revved it up. She told me it puffed a lot of black smoke and she got a CEL, which went out later. That just doesn't sound right to me. She has a CEL code in her ECU now.