Sure take out the garbage plastic and install Quiet long lasting non toxic cast Iron.
Then check your venting and also check your clevis hangers for proper support. You see a lot of bum handymen use band iron on plastic and never think about the possibility of sagging lines (bellies)and back pitching.
You should recheck your vent as their positioning from the trap and hopefully you didnt let some low life talk you into installing an AAV crap in your home.
Check your pitch and venting and possibly water jet your existing lines to make sure you have full flow. Good luck