There is no law that prevents a 19 year old from dating a 17 year old. However, if you have sexual relations you could have problems with having sex with a minor and be charged with that.
Can you date a 16 at 18 in Utah?
Utah is among the few U.S. states that have separate ages of consent for women and men. For women, the age of consent in Utah is 16 years old. While for men, it is 18 years old. No person under the age of 18, male or female, can legally consent to sex with a person who is more than 10 years older than the minor.