My almost 17 year old SS can't seem to take accountability for his actions.  He is diagnosed PDDNOS but on the lighter scale. So he does know right from wrong. Here is the recent shit he's been doing. I told him he could not go on his walk until his chores were done.  A minute later he's gone and his chores weren't done.  He wanted to go annoy his sister at the bus stop I said chores need be done first.  He left shortly after and chores were not done.  His dad grounded him from his phone but we keep it out in case his mom calls.  He ended up taking the phone. We are on a budget we buy  weekly groceries.  So what we have for that week is all we have.  Him and his sisters get to pick which snacks they individually want. We also buy lunch stuff for the youngest in kindergarten.  The older two eat lunch at school.  We tell my SS which foods he can eat and which ones to stay out of.  Before he eats his food he will get into both his sisters snacks and the youngest school lunch.  He also gets into my mothers food who lives with us. He will lie and say he didn't eat it and even has the audacity to ask his sister why she ate it.  SD called their mom to talk to her to see if she if she could SS to confess.  Of course she believed him because he said he didn't do it.  Even tho she was told he was the only one home she still blamed my SS. We got tired of it so my DH said he's not allowed in the kitchen without permission.  He will literally walk into the kitchen right in front of us without asking.  He told us he wanted to go to boys house after school to get help with school work. Dh said he needed to come home first then grams could take him.  My mom took him to the house and no answer. She told him to call the kid he said no answer .  He told my mom the kids name was James but he told my dh it was jack or Alex. Things seemed fishy to us.  He didn't even call anybody.  Turns out he lied he was really going to see his so called gf.  This girl he speaks of he claims she's not allowed to have peoples numbers without her mom's permission .  However she put her address in his phone.  We asked him why he lied he said because you guys told me no before.  Which he is lying about because the first time we said yes but her mom said they got busy.  We even told him before he could invite her to a party he said ok but thats when we learned he has no way to contact this girl. So pretty much we are to blame why he had to lie.  We tell him do your chores and you get paid. He don't do all of them. He wants a job we tell him get your grades up then you can get one.   He is a sophomore has 2 ds and 1 F. We said if you dont take high school and what we're trying to teach seriously you might end living in your moms basement playing video games.  So he says he can't do anything right and because we said that that's why he acting this way.  I said well why are you getting bad grades. He said I don't have the energy( he had labs done previously and everything is normal).  He wants to call me mom to piss his sister off but I told him he can call me by my name since his mother is active in his life.  That pissed him off so he called his mother to ask for permission to call me mom.  So he's accusing me of pushing him away since his younger sister is biological mine.  
when his phone gets taken away he doesn't change his behavior instead stays mad at us like we were the one who misbehaved. He blames his parents for why he's fat.   We've tried positive reinforcement that don't work.  Nothing works on this boy.  Hes not terrible where he's into drugs n stuff.  He just don't listen to anything, he lies all the time and doesn't put effort into making things better.  This isn't just a now and then thing.  This is every single day. He said he's trying to figure out how to be a teenager and just doing things his dad did as teen.  I asked him well what are those things your dad did.  He responded well actually I don't know.