I'm itemizing my deductions. I'm in Texas and using the general sales tax deduction. TurboTax is calculating my sales tax deduction as $0. IRS Calc is $487. How do I fix?

It depends. TurboTax uses the IRS optional sales tax tables and adds any big-ticket purchases you entered into TurboTax to figure out your sales tax deduction amount. You would need to enter the combined total state and local sales tax rate in the Sales Tax section under Deductions and credits. TurboTax also asks you to enter any nontaxable income in that section for calculating your estimated sales tax paid.

If you paid income taxes in another state, TurboTax would use the income taxes if they were higher than your estimated sales tax.

See this article and this one for more information on this topic.

You can preview your return before filing to find out how your taxes were calculated and view the forms TurboTax has prepared from your entries. See here for details.