I don't have kids but here is my $0.02 and you can take it or leave it.
FWIW the first thing I would do is take away ALL of his privileges. Number one is the Cell Phone. Also TV, computer, Internet the whole works. All TV, computer, Video Games etc. have to come out of his room to a PUBLIC place. No going out with friends. Take away car keys. He is 17. He can ride the bus to school. His friends can come to your house and only when you are home. If he has a job, you take him to work. He gets a ride home with you.
Now, offer him the following deal:
He can have these things back as he earns them. Cell phone, car, internet etc. he can earn back LAST, IF EVER.
Earning things back can be through work. Yes. Laundry, house cleaning, making meals, taking care of the yard, cleaning his room and keeping it clean.
You are his parent not his friend.
He is not 18 yet, he lives under your roof and under your rules. working to earn everything is what we all have to do. He had privileges because he was trusted. He broke that trust. End of story.
I am so glad I never had kids. They would hate me....