Sounds like the shotgun approach for repairs. A bad injector could be dumping excess fuel causing a too rich condition making the black smoke and maybe even cause the high temperature. As for the particulate filter and oxidation canister maybe you should wait and see if they clean themselves once the fuel issue is addressed. As for the turbo maybe it s fine once the fuel flow is addressed. If you can't do your own trouble shooting, have them proceed 1 item at a time, starting with the known problem, the injector.