I made the mistake of answering a question about foreign taxes "yes". I thought it was talking about sales taxes. How do I undo that?

You should be able to delete the Foreign Tax Credit forms and worksheets from your return. This procedure does work for  2016 online returns.

• Go to My Account at the top of your screen. From the drop-down, choose Tools.
• In the Tool Center, choose Delete A Form (see screenshot).
• In Review Form List, find the Form 1116 Foreign Tax Credit Comp Worksheet, and choose Delete. Do the same for Form 1116 if you need to.
• On the screen Delete Selected Form, select Delete. After the screen Form Successfully Deleted, go back to the forms list, and verify that the form has been deleted.

If you entered your sales tax in the Foreign Taxes section and said you wanted to take an itemized deduction, you can go back through the section and remove the amount that you entered

Except that when you say DELETE A FORM and then select the 1116 and confirm delete, and then TurboOnline confirms "I have deleted this form", the form is NOT GONE.