The teen years are all about transition. They are the cocoon between childhood and adulthood. During this period kids are...
1) attempting to determine who they are as an individual,
2) pulling away from their parents as a natural part of this process, and
3) doing all of this in the midst of a flood of hormones.
Any of these has the potential to cause conflict. The combination of any two or more guarantees it.
But not every spat has to become a war.
Be patient. You need to pick your battles because they won't.
Think about it.