It depends on the college you attend. All colleges have their own rules, both public and private. Some accept no AP credits regardless of how well you did. “Passing” the AP test probably means you got a 3. For some schools it may help you with general education requirements, but a 4 or 5 is usually required for specific course credit. Engineers need breadth as well as depth, just like any other field.
The AP credits are never “useless”. While they may not help you with your college credits they can help you get admitted to the college you want to attend. They show colleges that you are taking the most rigorous classes offered by your HS and can do okay in them (higher test scores show up better, btw). You are a multifaceted person, not just a STEM one. The knowledge gained makes you a better person.
Often students are admitted to the whole college/university regardless of the proposed major. Sometimes the admission is school/college division within the university. Your entire HS career counts, not just your math and science classes. Look at your state flagship U’s engineering requirements. Along with the obvious STEM courses you will likely find other required classes.