Mechanic problem

I found a mobile mechanic on facebook. He had people recommending him on there. I asked him if he'd come diagnose it he said yes. I asked him when he doesnt respond for 3 days. Finally says he will today. Then today becomes tomorrow. He finally comes and diagnoses it and says he will let me know when to take it to his shop. He BSes for 4 days on bringing it and against better judgement I still go with him (because I paid a $78 diagnosis fee and would get recharged if I went somewhere else). I bring it to him.

A couple days later he replaces the catalytic converter, the gasket, and according to him some sensors. But heres the thing he says he "doesnt have time" to put on the last sensor (throttle protection sensor). I say its weird he cant just put it on. I get it its idling weird. His mom tells me if I have problems just bring it back and he will put it on. He says I should be able to do it...

I get home take a look and its behind a bunch of shit. I have to go buy special starfish security screws and the sensor. Long story short cant get it on. I message him and ask him if he can swing by and do it its almost on but the screw is gonna strip if I keep trying. He ghosts me for 4 days. Finally responds and says he will do it tomorrow. Tomorrow comes and his uncle supposedly gets in a wreck. Then he ghosts me again.

So then I see he responded to someone on a group asking for a mechanic that hes a mobile mechanic and can do work on their stuff. I then annoyed responded to his post "you cant finish your work or respond but you can get more work?" And we go back and forth abunch. He's trying to make me feel bad but am i really out of line? We have been going back and forth just arguing. He wants me to take it down I refuse. Then he gets the person who made the post to delete it.

He now wants to come fix it for free. I said no dont come here. I feel like we will probably get in a fist fight or something because I'm really pissed off and he's got abunch of wrestling pictures on his Facebook and Im liable to punch him and it possibly will or wont go my way. Who needs the headache? Ill pay someone else. But am i really out of line? Hes trying to make me feel bad. He keeps calling he knows where I live. Its not gonna be pretty if he shows up.