When applying to schools and selecting engineering as a major, many schools recommend selecting two majors in the college of engineering. Why is this? Does it hurt me to select something outside the college of engineering for one of the majors, for example, computer science?
Many students applying to engineering would rather get into a second choice engineering major than an outside major. In other words, becoming an engineer is of prime importance. So engineering schools might suggest to keep your second choice within engineering as a way of saying, hey, we can’t promise you your first choice due to the competition for spots, so if you really want to be an engineer, your odds are better if you keep your second choice also within engineering (even though we can’t promise you your second choice either!).
If CS is acceptable as a second choice major/career and you’re ok with having only one shot at the engineering school, then your plan is fine. Note that CS is also “impacted” at many schools, so you’re not necessarily improving your odds of admittance by going outside the engineering school (but that depends on the particulars of the university and your own profile/grades).