It is not legal to move out at the age of 17 in Texas, unless one has been emancipated by the courts. In the State of Texas, the "age of majority" is 18 years old, according to FindLaw. Therefore, a minor who is 17 years of age is still under the control of, and is the responsibility of their parents, unless emancipation has been grated.
Under Texas state law, minors may petition the courts for emancipation. Being emancipated means that the minor is considered an adult according to the law. Those requesting emancipation must be 17 years of age (or 16 if living apart from parents or guardians), must be self sufficient, without having to rely on others, and able support themselves financially. If all conditions are met, the minor may file their petition, however, unless there is a clear case that one's parents have failed in their responsibilities it is unlikely that emancipation would be granted, according to the Legal Information Institute.