[KatoKato]

For my daily drivers I have always added a large does of fuel injector cleaner to the tank of gas before an upcoming oil change. (Amsoil PI or equivalent)

Since the purchase of my 911 I have never done this as I'm worried that the cleaner might cause more harm than good in bringing through 20 years of gunk upon first application. (as far as I know the gas tank is original and perhaps the lines as well).

Does this sound reasonable ?
Any comments would be appreciated.

Thanks,