No one can look at your tax return. TurboTax is not a CPA firm; TurboTax provides software for you to prepare a self-prepared tax return. Not sure what you mean by a "last minute" extension--the deadline for requesting an extension was April 18, 2017. An extension only gives you extra time to get your documents in order to file. It does not give you extra time to pay any tax due. You were supposed to pay the estimated tax due by the deadline of April 18, 2017.
If you can clarify where you think you may have a mistake on your return, someone will try to help you. If you have tax due, and have not paid anything yet, your interest and penalties are accruing.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
