I have raised a son who is now 21 and I have a stepson-to-be and he is 14. So, I've been there and know EXACTLY how you feel.
For one. You MUST stop yelling at him. Yelling is an extremely ineffective method and is simply a release of your own frustrations, and is not teaching him how to control his own anger and frustration. In addition to that, the yelling is TEACHING him that he doesn't actually have to listen to you until you yell. So, you are perpetuating the very behavior you want to stop. And the last reason to stop yelling is that it isn't a behavior you would do to another adult that you worked with, for example, or a fellow parent. Therefore, it isn't appropriate to yell at him either. As he moves closer and closer to adulthood, he needs to be treated more and more as an adult with adult consequences for his behavior.
Developmentally and emotionally, your son is moving toward manhood. When he is a man, he is going to need to provide for his family and be a decision-maker and be self-sufficient, etc. In order to accomplish those things, he needs to pull away from you, as his mother, emotionally. What woman wants to marry a momma's boy? What man wants to be percieved as a momma's boy? Your son has to learn how to honor and respect you as his mother without appearing weak and wimpy to his friends, and he doesn't know how to do that yet (it is the same with his teachers and his father). All he is feeling is the innate NEED to not listen, to not obey, to not comply with what he is being told, etc. Your opportunity is NOW to teach him how to balance his need to act like a grown man and to respect the authority that is still over him.
So, just go through your mind and decide what the real world consequences are to doing some of the things you mentioned. If he was living in his own apartment right now, or going to college, or going to work, what would happen if he didn't complete an assignment, or clean up after himself, or be late to work?
I remember one time when my son was 14 he complained about his math homework. He said, "I'm not going to do this assignment, it's stupid." and instead of trying to talk him into it or explain why he needed to do his homework or whatever, I simply shrugged my shoulders and said, "Ok, then don't do it." and he said, very surprised, "I HAVE to do it or I'll get in trouble!" and I said, "Then get in trouble." He just didn't know what to do. I had called his bluff, and and he wasn't prepared. I remember him turning around and walking up the stairs and saying under his breath, "I'm going to do my math."
Another time, he complained about how a teacher just wasn't teaching something right, etc, and I listened to him and simply said, "I understand how frustrating it is to have a teacher who isn't helping you to understand, however, it isn't the teacher's grade that will end up on your transcript, it is yours. So, YOU need to figure out how YOU are going to learn this material. Do you need a tutor? Do you need to get a friend in your class to help you?" and the conversatin continued until he had several options available for him to take responsibility for his own learning and then he had the power to decide how he was going to proceed to help himself.
When it comes to school, you just might need to let him get in trouble for not doing his homework, or whatever, because in college there will be no mother or father to remind him. He will need to do it on his own. In fact, of my 4 children, two who are graduated from high school and two how are currently in high school, I hardly ever remind them to do their homework. It is their responsibility, and if they don't do it, then they will suffer the consequences on their own. Period.
About the carpool, I'd instruct the carpool people NOT to wait on him more than 5 minutes. If he doesn't get his ride, what would an adult have to do? Well, one solution is to call a cab. Taxi's cost money and you can't always rely on their timliness. My good friend who is a single mom did this to her son. She instructed him that if he ever missed the bus or his carpool, then he was to call a taxi to take himself to school and he needed to pay for it himself. It took exactly ONE TIME for this to happen, and he never missed his bus or carpool again.
Chores. Now that is another matter. No person comes to you as an adult and tells you when to do your laundry or clean up your kitchen, and if they did, you'd probably be insulted. Remember that. When you tell a young adult to do something "now", it is insulting and they will resist. So, let him know in advance when you want the job done by, and if it isn't completed, what the consequences will be. For one, I don't require that they clean their rooms. That is for them to determine. Just learn to close the door if it bothers you.
Let's say you want your son to put his shoes in his room and you are fixing dinner. Say, "I want you to put your shoes in your room before dinner." Simple and sweet. You also need to figure out what is the consequence of him not doing that. Be creative. One option is to put them in a box in the attic (or some other remote place) and he won't be able to have them back until he earns them back by doing some kind of chore (like cleaning out the car, for example). If he loses some things because he didn't listen to directions the first time, and then he had to earn them back, he'll soon figure out that listening the first time will save him quite a lot of trouble.
I taught my kids from birth to listen to me the FIRST time when I am speaking in a normal voice. I do not and I will not yell at them. If I have to repeat myself or I feel myself getting angry, I will simply say to them, "I do not feel like you are listening to me and that is making me angry." or I will say, "If I have to repeat myself again, there will be a consequence." (I will say that about the 2nd time or so) I try to make it as close to a real life consequence as possible, or something that directly correlates to the issue. I've taken away the cell phone when they have talked back, explaining, "If you cannot use your mouth correctly, you don't need to use your mouth." I've made them work to repay debts. I've let them wear dirty clothes if they forgot to do their own laundry. The list goes on and on.
I hope some of these suggestions help. My kids are wonderful people and are a joy to be around and they are very loving and I wouldn't have traded being their mom for anything in the world!
My final word is: parenting changes in teenager land. If you try to treat your teen as you did when they were younger, you WILL get resistence, either overtly or covertly. They deserve more respect than that. They need to be taught to deserve the freedom that is gained in adulthood balanced with the responsibility required by adulthood. The more you treat them in this way, the more they will respond with the maturity you are working toward.
All the Best,