No, you are unable to e-file your return if it is found to contain an override in your return.
The TurboTax CD/Download software lets you override, or replace, the amounts it calculates. Because overriding can only be done in Forms Mode, you won't be able to do this in TurboTax Online.
When you run the final review, TurboTax will let you know if there are any overridden values in your return. If there are, you'll get an error message if you try to e-file your return.
