AP Testing in College but not for credit.

My situation is a bit complicated so bare with me as I explain this.
I was a 4.0 student throughout my highschool years (about 1.2k ranked nationally, #2 in the state), except my senior year I got hit with the sweet plague of senioritis and got about 3.6 gpa, making my overall gpa about 3.8. Now that being said, I took many AP courses which I passed the class but failed the exam with scores that ranged from 2-3 (I did pass few with 4). Obviously, I wasn’t able to get credit for those classes and I had to retake them in college
I got into a local state university with 80% acceptance rate, and got 2.0 gpa in a very competitive subject.
Seeing this I realized college may not be my thing and I didn’t go to school for half a year.
Then I transferred to a community college in attempt to recover my gpa and perhaps aim for an ivyleague school.

I am getting 4.0 gpa in my community college, with a lot of Fs in my record from my previous institution and some volunteer hours in my field.
However to raise my chance of getting into the ivyleague school that I want to go into, I wish to retake my AP exams.
I did get 1500 for new SAT (the first time I took it was about 1650 in the old exam), but plan to retake it for better grade.

I have ran across some articles but they were all talking about taking AP exams to get it into college credit. I am not looking for this but I want to show colleges that I am capable of passing these exams. Would this be helpful or necessary? Am I supposed to do this? Please guide me. Thank you guys in advance.

For starters, Senioritis is not a disease, it’s a choice.

AP exams are “advanced placement” exams. They’re given to high school students, not college students.

Look at taking SAT II exams instead to show mastery of the subject material.

Basically the subject tests, right?