Yes, you may be able to deduct the sales tax paid when you purchased your mobile home.
To find this in TurboTax Online, open your return and click Search in the TurboTax header. Type in "sales tax" and hit Enter. Click on "jump to sales tax" to go to page titled "Let's Compare Your Sales Tax and Income Tax." Click Continue.
Choose the Easy Guide and work through the interview until you come to the page titled "Major Purchases." Click Yes.
Enter your purchase information on the next screen (see screenshot below - click to enlarge), including the sales tax you paid.
Please note that you will only be able to take this deduction if you itemize on your return. TurboTax will give you the greater of the standard deduction or the itemized deduction based on your particular situation.