Will a high Sat score (1590) but very low essay score (5,3,6) affect UC admissions

I got 790 on math 800 on reading and writing but 5,3,6 essay (14/24) I am planning on applying to all of the UCs including UC berkeley and UCLA. Those schools require the sat essay. Will this significantly affect my chances of getting in? Also, for ivy schools, would not sending in my essay score affect my chances too?

I’m also planning to major in STEM. So would that make the admissions officers more inclined to ignore my essay.

The UC’s will be more interested in your personal insight essays vs. your SAT essay score. Congratulations on an excellent SAT score and hopefully you are a Junior applying for next year. Now you can spend the rest of the year studying for the SAT subject tests for the UC’s and brain storming ideas for your personal insight essays.